8-Bit Computers

[RoboCop]

In this topic, I will be explaining on 8-Bit Computers. “What are or is an 8-Bit Computer and what does it mean” you may ask? Well, very early microcomputers were powered using an 8-Bit processor that was first created in the 1970s and became popular around the 1980s. For the sake of keeping this topic short, I won’t be explaining a lot about IBM Mainframes, 8-Bit Game Consoles or on 8-Bit computer brands that failed to be a commercial success nor those that weren’t iconic for gaming. For clock speeds and voltages, 8-Bit processors vary on which of those adjustments are recommended and depending on the way the circuit board is constructed on using the Capacitors, Resistors, Heat Sinks, Power Supplies and providing laminar flow for the air vents. And also on NMOS and CMOS – where NMOS logic was initially used for most of the 8-Bit CPUs; whereas CMOS consumes less power for some later revisions of those CPUs. It is important for the computer to not generate too much heat as that can melt the soldering from the circuit board, but most PC manufacturers have Planned Obsolescence for capitalism purposes. Also, quite a lot of 8-bit computers were mainly the UK and US made, whereas the MSX range was kinda in a bubble as those were mainly for Japanese markets until around 1984.


Before I explain each of the 8-Bit computers let's take a closer look at the top 3 processors:-

MOS 6502:-
This processor was found for the Atari 2600, Acorn BBC, Atari 800, Commodore 64 and the Apple II. MOS was acquired by Commodore after it released its 6502 CPU and continued its production until Commodore got bankrupt in 1994. The advantage was that the MOS 6502 was cheaper to produce but had fewer transistor counts than its rivals. Also, NES had used a Ricoh 8-Bit CPU that had the MOS 6502 instruction set. But Motorola claimed that the MOS 6502 had Motorola’s patented processor technology from the 6800 and filed a lawsuit against MOS for cloning the 6800.


Intel 8080:-
This Intel CPU had more transistors than the MOS 6502 and Motorola 6800, but was initially designed for IBM PCs and not for low-cost computers. The downside was it was harder for the assembler to code than the Zilog Z80. And the i8080 was considered to be successful mainly in Eastern Europe including USSR.


Zilog Z80:-
The Z80 is the superset of the i8080 and is compatible with the i8080 instructions. The Z80 got a higher recommended clock speed and transistor count as well. It was created by former Intel employee Italian Physicist Federico Faggin, who left Intel in 1974 and founded Zilog during that year with Ralph Ungermann. And the Z80 had nearly twice the clock speed than the MOS 6502 and are still technically used for simple or scientific calculators but no longer for high-end Texas Instruments Graphic Calculators as they have moved on to ARM processors for the TI-Nspire series.


So without further ado, lets start with the most recognisable 8-Bit computer the Commodore 64:-
The C64 was released in August 1982 by Commodore Business Machines with a MOS 6510 1MHz processor and 64KB RAM. It was the successor to the CBM VIC-20 as Commodore CEO and Founder Jack Tramiel wanted to have a new 64KB RAM machine as well have the C64 at an affordable price with the essential colourful graphics at the maximum resolution of 320x200 with a 16 colour palate. They use data medium by using a Cassette Tape or a 5-inch Floppy Disk. However, Jack Tramiel had some major disagreements with some of his corporate members and Irving Gould who had been bickering since around the 1960s, and left Commodore near January 1984 and said: “they had disagreed on the basic principles on how to run the company”. Sadly most of the later models of the C64 and the 128KB RAM version known as the Commodore 128 was not as successful as the original version. This was mainly because of the introduction of new 16-bit computers like the Macintosh 128K, Amiga 1000 and the Atari ST near 1985; as the C128 only had the newer MOS 8502 processor and the Z80B processor clocked at 2MHz each. And C128 had some flaws as the “C64 Mode” wasn’t that reliable and was too expensive to be affordable for a bulky 8-bit computer – which was why Commodore was focused on the new 16-bit powered Amigas.

Pros:-
>> Got colourful graphics and good sound quality
>> Many games and software parties were supported for the C64
>> Allowed the use for floppy disk drives for impatient gamers as cassette tapes take longer to load
>> C64 had some cool accessories like the Mouse, Printer and Modem, even the Light Pen and Light Gun
>> And it was cheaper than the IBM PCs, Apple II and the Atari 800.

Cons:-
>> The BASIC coding was complicated and quite counter-productive
>> The MOS 6510 was a very slow CPU as the MOS 6502 can perform nearly twice as fast and the 6510 was not as fast as the Atari 2600
>> The ivory brown colour is not as radiant nor nicely designed, but that’s 1980s computers for ya
>> A separate manual is needed for programming in Commodore BASIC V2 and for using LOAD “*”
>> C64 uses a bulky external power supply and requires an external floppy disk drive and cassette player, as they aren’t built-in
>> The 160x200 resolution for most games don’t look appealing due to the wider pixel dots shaped like tiny slots
>> The F-Keys from F1-F8 look weird as they have a combination of both F1/F2, F3/F4, F5/F6, F7/F8

Improvements that should have been made:-
>> Well not let Irving Gould make our key leader Jack Tramiel leave Commodore for better later revision models, of course! (Why can’t some folk just get along and stop being insolent?)
>> Well the 160x200 resolution isn’t that worth for the C64 so remove it and had more colour support for 320x200 maybe?
>> Make the F-Keys look neat and maybe have it from F1-F10
>> Introduce the C128 at an earlier date, make it more cost-reduced and maybe keep the MOS 6510 as a co-processor for true native C64 support
>> And they should of at least provided a decent manual as well show them some interesting tips on using the C64


Acorn BBC Micro:-
This computer was produced for the BBC Computer Literacy Project in the 1980s. It became a direct rival to the ZX80/ZX81 as well as a British cheaper alternative to the American made Atari 400/800 and the Commodore PET and VIC-20. Acorn Computers was founded by former Sinclair Radionics Ltd employee Chris Curry, along with his Austrian friend Hermann Hauser in 1978. The BBC Micro A had a RAM of 16KB and the B Model with 32KB RAM. Due to its success and competitive prices and some reliable accessories and peripherals that nearly 78% of the UK schools, colleges and universities had been using the BBC Micro during the 1980s for educational purposes. However, the downside was that BBC Micro A/B had very little RAM than its rivals that didn't have the ability for additional software features until the BBC Master 128 with 128KB RAM became a successful enhancement over the original in 1986. The Master 128 was wider and a little thicker but had Numpad keys and the cursor keys in a neater position. Even though the BBC Master 128 was more popular when they eventually replaced the originals, it contains 2 Cartridges slots above the Numpad keys. Unfortunately, not all of the BBC software was compatible with the BBC Master 128 nor with the co-processor addons as they only worked at a specific clock speed as well had some complications with Z80, Intel CPUs and the early ARM co-processors. The Tube interface had contained the Acorn RISC Machine or ARM processor for the BBC Micro to be upgraded but cost around a massive £4000.

Pros:-
>> Was cheaper than the Atari 800, Apple II, C64 and the IBM PCs
>> It had a integrated BASIC assembler
>> The Tube additional MOS 6502 second processor that was required for David Braben's legendary Elite game gave it a revolutionary enhancement
>> Was popular in most British schools and colleges as their disk drive had the faster loading speed advantage
>> The controls for most software was primarily based on the cursor keys, space bar as well as the red F-Keys, whereas most 8-bit computers needed various interfaces like Sinclair II Interface, Kempston as well as certain controller ports
>> Had similar Teletext and ZX Spectrum graphics but aren’t liable for “colour bleeding”

Cons:-
>> The MOS 6502 was cheaper but slower as the processing and rendering of the images takes a bit more time to finish
>> Teachers mainly had to supervise their young students to handle the floppy disk with proper care as well show how to load the disk using [Shift+Break] keys
>> Their second processor addons and BBC Master 128 was not compatible with most of the older software
>> Because the BBC Micro has an internal power supply makes the casing more beefed up and huge, but worse of all easily overheats as they didn't have better ventilation nor enough cooling fans
>> The BBC Micro Model B and Master models was a bit expensive
>> The Model A and B also had very low RAM of 16KB for the A and 32KB for the B
>> The software for the BBC Micro was more expensive than the C64 and ZX Spectrum

Improvements that should have been made:-
>> Well maybe if Sinclair as well as Curry & Hauser had made up and not split, as they would have used that Acorn BBC technology as a Sinclair ZX Spectrum’s high-tier 8-bit range with the monitor, DOS and floppy drive
>> Well had a magnetic shield for 5-inch floppy disks to prevent the magnetic data contaminated by touching or exposed to dust and foreign material
>> Add more heat sinks and a fan maybe for all models since the internal power supply is the source of excessive heat


Atari 800:-
Since Atari had very much success with the Arcade Pong machine and the 2600, they had created the Atari 8-bit computer like the Atari 400 or the high-end Atari 800. The Atari 400 model had a thin membrane keyboard while the 800 had full-travel keys. The newer 1200XL came into the computer markets in 1983 but wasn't affordable as it had cost $899 and quickly became discontinued. Since Atari was under ownership with Warner Communications since 1976, they appeared to create some setbacks as Atari's separate divisions didn't use their efforts and cooperated due to staff abuse. Eventually in the aftermath of the 1983 Video Games Crash and Atari took heavy financial losses until it was bought by former CEO of Commodore, Jack Tramiel in July 1984 - 4 or 5 months when Tramiel along with his sons Sam and Leonard, left his own company as he was the founder of Commodore. During the Tramiel era as well as having some direct computer wars with Commodore he had made some cost-reduced versions of the 800XL known as the 130XE or 800XE with enhanced graphics but had some technical flaws. The Atari 8-bit computers were eventually replaced by the Atari ST starting with the 520ST in June 1985 and became a successor by then.

Pros:-
>> Both the 400 and 800 had a very early head start in Xmas 1979 as C64 as well some of its British 8-bit computer rivals arrived near 1982
>> Had powerful graphics and 256 colours
>> It can support ROM cartridges
>> Their keyboard design and GFX was suitable word processing
>> The 800XL was considered the best selling range due to its lower cost-reduced price and promising improvements over the 800 model

Cons:-
>> The original 400/800 was far too bulky but I suppose they used that for powerful GFX
>> The expensive 1200XL was considered a commercial failure and was too pricey
>> The Tramiel 800XE or 130XE ranges weren’t as reliable as the original models.
>> The 800 launch price was too expensive at $1000
>> The Atari 400/800 series didn’t sell as well as the Commodore 64 due to their higher price

Improvements that should have been made:-
>> Well Atari did had a lot of bad luck during the 1983 Video Game Crash, so maybe if they sold their company to Commodore or maybe some other computer company, but Gould would of disagreed
>> Even though Tramiel took over Atari as Atari Corporation in 1984 when he left Commodore, he would coped better if Atari didn’t had lawsuit battles from his own company
>> Tramiel may of been too focused on the Atari ST but could of double checked on his redesigned 130XE, despite his success on the Atari 7800 and the Atari 2600 "Junior" cost-reduced console
>> Well we may not know the full story of the staffing problems under Warner's ownership but it would of been better for Atari Inc to do things more independently, but that is very much everyone's guess.


Apple II:-
A computer designed by Apple Co-Founder Steve Wozniak and released in 1977 powered with a MOS 6502 required for this pricey machine for slight cost reduction. Unlike other 8-bit computer models that didn't looked as sleek and didn't had a wooden casing like the Apple I in 1976, the Apple II became a useful computer for word processing and other office purposes. The Apple IIe had a amazing 10-year retail availability since 1983, along with revisional changes to the PCB and the ergonomic design. The Apple IIe Platinum included the Numpad which was released in 1987.

Pros:-
>> Was released at a very early date
>> The Apple IIe range was the best enhancement of the original Apple II model
>> The design model looked a little rugged and robust that it allow to stack 2 Floppy Drives and a Monitor
>> Allows certain expansion slots for additional purposes

Cons:-
>> Was extremely expensive to buy
>> The Apple II range used the slow MOS 6502 but I suppose they used that to avoid having their higher selling prices and their casing from overheating

Improvements that should of been made:-
>> Well for a powerful and expensive computer like that maybe used the Z80 or even the i8085
>> Maybe had a cost-reduced version of the Apple II range
>> Well Steve Jobs would have encouraged his company to adapt and focus more on the Macintosh and not be forced to leave Apple in 1984


Amstrad CPC:-
The Colour Personal Computer or CPC was Amstrad's first low-cost computer launched in 1984. Even though the original CPC 464 had a built-in cassette player and coloured function keys but didn't include the actual F-keys until the 6128 model was launched in 1985 with 128KB RAM as the original only was 64KB. Before Amstrad entered on selling their computers, the founder Alan Sugar stated, "We needed to move on and find another sector or product to bring us back to profit growth". Because of its amazing 8-bit colours as well with a amazing LocoMotive BASIC v1.0 and capable of running CP/M software made this 8-bit UK computer a great success, but didn't succeed on making a 16-bit successor that would last as it's predecessor - maybe because they didn't focus on adapting to 16-bit processors like the Motorola 68000 nor the Intel 80286 for their PCW range.

Pros:-
>> It’s had a slightly faster Z80A CPU at 4MHz than the older Z80 revisions
>> The CPC 464 can support up to 27 colours
>> It’s got a built in tape drive
>> The graphics was slightly improved than the ZX Spectrum and C64
>> It can support Atari Joystick ports
>> The 464 keyboard got some useful highlighted colours to indicate function keys (not F-keys)
>> The CPC 6128 updated model had extra 128KB of RAM and a built in Floppy Drive

Cons:-
>> The colour monitor was a bit small as well having to choose between the cheaper green monochrome or the colour version
>> The CPC was released 2 years later from the popular C64 and the ZX Spectrum release date, which didn’t had much of a head start chance
>> The CPC 464 model was a bit bulky and too wide
>> The cursor keys was a bit to far to reach and had the Keypad keys closest

Improvements that should of been made:-
>> Switch the location of the cursor and keypad keys
>> Well had the CPC at an earlier release date, as brand new 16-bit computers arrived in 1984
>> Maybe had the CPC 464 equipped with a built-in floppy drive as tapes are too slow and would save more space for a 128KB RAM model
>> Well they should of had a 16-bit successor and not dwell on making a GX4000 console that failed as well used a Z80 processor. But why couldn't they and got stuck with the Z80, eh?


Sinclair ZX Spectrum:-
The ZX Spectrum was the successor to the popular ZX80 and ZX81 but allows 16 colour support with RAM upto 48K followed by 128K RAM in 1985, with a Z80 at 3.5 MHz. Devised by Clive Sinclair and manufactured by Timex in Dundee, Scotland which was first released in April 1982. This computer had became C64’s rival but mainly in Europe as they didn’t had the NTSC until Timex had produced an “American” version of the ZX Spectrum. When Sinclair struggled to gain enough profit and market share near 1984, he made a deal with Alan Sugar from Amstrad in 1986 to sell his Sinclair ZX Spectrum range to Amstrad. Amstrad then produced their ZX Spectrum models, such as the 2+, 3+ and the 2A+. By 1987 Amstrad introduced a Magnum Light Phaser for supporting Light Gun games. But by the time the 3+ was released it was considered to be Sinclair’s final computer ever made as their 16-bit successor, the Sinclair QL failed to achieve any signifiant success. Sinclair Research suffered heavy financial losses in the late 1980s, and had inevitably discontinued its entire computer and most of its hardware ranges in 1992.

Pros:-
>> The Sinclair BASIC programming and 48K BIOS were easier to program and used “shortcut hot keys” like [LOAD “”] used without typing more than 3 keys
>> It’s got a fast Z80 processor that can be used for CPU intensive tasks
>> It was cheaper and affordable than its rivals
>> It can support Atari Joystick ports, but only with the Kempston Interface
>> Amstrad produced a Light Gun to support ZX Spectrum 2A+ Light Gun games
>> The original 48K model was very compact, cost-reduced and light
>> Thousands of games were supported and made for the Spectrum
>> The 128K versions allowed games for enhanced sounds and more gameplay features
>> The external power supply allows heat to be separated away between the powerful CPU and the power supply itself

Cons:-
>> The ZX Microdrives was supposed to be the smaller and cheaper alternative to the tapes, but wasn’t reliable and fast enough
>> It didn’t had a Floppy Disk drive until Amstrad supported it for the 3+ model in 1987 which was too little too late
>> It didn’t had as much colourful graphics as the C64 nor the Atari 400/800 as they were pretty much like Teletext quality
>> Graphical image colours had to be kept in an 8x8 attribute block and can only use 2 colours per block, which are required to prevent attribute clashing or “colour bleeding”
>> The original 48K rubber keys were distinctive but not as comfortable like IBM Model M Keyboards
>> The 16K model was pretty much pointless as the 48K model was affordable enough
>> ZX Spectrum was not successfully built nor popular for the NTSC region like it’s US counterpart, the Timex Sinclair 2068 and the Timex Computer 2048, and isn't compatible with the original ZX Spectrum games - like a Regional Lockout
>> The newer ZX Spectrum+ was not as reliable as the 48K model
>> Because the early models of the Spectrum only had a BASIC BIOS screen and supports only tapes, that it takes nearly 3-5 minutes for it to load completely with that dreadful screeching noise – so you won’t have an excuse to get up and make a coffee or have a loo break eh?

Improvements that should of been made:-
>> Maybe had a tiny cooling fan or heat sink and increased the Z80A clock speed to 4MHz not 3.5MHz?
>> Maybe the 48K should had the cursor keys added separately from the 6-0 keys
>> Maybe the 48K should also had a wide space bar
>> The 48K model should maybe have Reset button and Power switch
>> Well maybe the 256x192 resolution is not wide enough for an 8-bit computer to display so maybe a little wider as long it fits within the 8x8 blocks
>> Well pretty much ditch the ZX MicroDrives project for 5-inch floppy disks
>> Maybe had the 128K version done earlier and ditched the ZX Spectrum+ project?
>> Well maybe if Sinclair didn’t got split up and got in direct competition by Acorn who were founded by former Sinclair employees
>> And maybe had more AMX mouse support for moving the text cursor as well playing some Paddle games like Arkanoid, Breakout or Pong?
>> Maybe Timex should have had more effort for producing the NTSC versions of the ZX Spectrum


Arcades:-
Well Arcade machines are different because they aren’t for home nor for office use, obviously. Arcade games are mainly for attracting gamers as well on using their higher graphics and processor power as their rigs can be big enough to push their games to their limit. Mainly for 8-Bit Arcade games, well they were popular on using the Zilog Z80 as it had the best processor speed – as well as having multiple co-processors for sounds and graphics during the 1980s. Also the Motorola M6809 was also used for Arcade games and had a extra 500 transistor count than the Z80, but didn't had a higher clock speed than the Z80. And most of the 8-bit Arcade machines became replaced by the M6809's successor, the Motorola 68000 16/32-bit processor and became a popular replacement.

Summary:-
What have we learned on the history of 8-bit computers and how they evolved? Well we now know how the popular ARM came from Acorn Computers in 1985, that was used in handheld machines like the Palm TX, Apple Newton PDA, Game Boy Advance as well as the popular Raspberry Pi. But the ARM is a RISC instruction set and isn’t designed to be as powerful as the Intel x86 archs. Of course those early 8-bit computers did had some early technical flaws and allowing their customers to know how to operate and interact with those computers, as they were the first to appear in consumer markets. Because 8-bit softwares had very little medium storage space, that some software developers had added some unnecessary features or hadn't made their coding optimised for smaller and faster loading became a issue for review ratings. Text-based Adventures as well as 2D Adventure and Platform games had some paths or gameplay areas that had misleading clues or boring images that can never match with 32-bit multimedia computers, had a negative impact on their software quality. The worst thing was because they had made cross-platform softwares for too many 8-bit computers and consoles, that they didn't had enough time to "doubel chk" on typos or those nasty glitches, which uncommonly occur on most softwares and couldn't be patched. Personally I found those Text-based Adventure games too awkward as well having to retrace my steps as some empty rooms and rogue items was very pointless, that its 2D counterparts had the same thing which caused some confusion and wasted their reserved data for that and made their gameplay completion too short. And lets not forget on how much compression technology is used from the bulky Apple II to the latest iMac Intel sets with the ultra thin monitor. Even though making a computer is really extremely hard to produce, and some key employees who had worked on countless efforts had revolutionised the industry. Sadly as 8-bit processors in their original NMOS design that had appeared in the Microcomputer Revolution weren't as fast and used less power until the CMOS design came in too little too late. Because the advantage of 8-bit CMOS designs are: very low power consumption, lower complexity, high noise immunity and doubling its recommended stock clock speed. But sadly that didn't happen to a lot of 8-bit computers before Intel 80386 arrived in October 1985 and upgrading an existing 8-Bit NMOS CPU for a CMOS version doesn't work that way as "OUT (C),0" aren't compatible on CMOS.

Possible FAQs:-
Q: Are 8-bit games forwards compatible for newer 16-bit and 32-bit games?
A: Not natively as 8-bit CPUs was used as co-processors for the Sega Mega Drive/Genesis to play Master System carts with the Power Base Converter and for the Game Boy Advance to play Game Boy carts.

Q: Why couldn’t 8-bit machines use CD-ROM technology or that?
A: Well bare in mind that CD tech was in its early stages in the markets as well had some “teething” problems, but was too expensive. However the Acorn BBC had supported LaserDiscs for the Doomsday project package that had LV-ROM discs, which store a whopping 325MBs in 1986!

Q: Well that's quite a lot of various 8-bit computers that were in the 1980's market, but was there any need for having so many?
A: Well not really, because 3rd Party software companies kinda struggled to figure out the 8-bit computer's compatibility with various models, and because certain Computer companies was too arrogant or too fussy that they created too many various models with different instruction set processors - not to forget that Sinclair, Commodore and Apple split up, had made it too counter-productive for software companies to thoroughly test their games and programs for better reliability.

Q: I've noticed that not many 8-bit computers, as well as 16-bit computers, don't have a cooling fan, was there any need for one?
A: Yes definitely! Even though the MOS 6502 clocked below 1MHz may not generate a lot of heat but those early 8-bit processors weren't energy efficient as they consumed too much power - until now with better semi-conductor metals. Besides that is mainly the reason why Single Board Computers inside a protective casing should have a fan for better circulation cooling.

Q: Which 8-bit CPU was the best for computers built in the early 1980s?
A: Well it has to be the Zilog Z80 as it was made as the enhanced version of the Intel 8080, and the MOS 6502 was cheaper but didn’t match the power of the Z80. But I suppose it was because Commodore wanted to manufacture a low-cost 8-bit computer as well not have overheating issues.

Q: Would things had been better if Sinclair didn’t got split up when Acorn was founded by some former employees of Sinclair?
A: Well it is very unpredictable and very much everyone’s guess. But both Sinclair and Acorn started to go completely downhill in the 1990s as they failed to achieve enough positive reviews and better reliability for their 16/32-bit computers: such as the Sinclair QL M68008 powered computer wasn’t a commercial success – and the Acorn Archimedes couldn’t compete when the Windows 3.1 and Windows 95 arrived. And both Acorn and Sinclair – including the Amstrad CPC that, didn’t had promising 8-bit computers for NTSC regions and only sold their computers a lot mainly in Britain.

Q: Would things also had been better if the computer founders Steve Jobs from Apple and Jack Tramiel from Commodore didn’t had no choice but to leave their own company in 1984?
A: Well...yes sort of. Like Sinclair, both Atari Corporation and Commodore struggled with their key workers left and their profits and market shares fell steeply near 1992-1994. Which lead to both the demise of Commodore and Atari Corporation – founded by Tramiel in 1985, hence it was more or less considered a dead heat. Apple was only lucky enough to have Jobs returned in 1996 and was back in for the profit.

Q: Which was the best 8-bit computer ever made for gaming?
A: Well personally high-end 8-bit computers was too expensive to buy, so the C64 and maybe the ZX Spectrum was the best computers made in the 1980s. If you want a better colourful GFX and a fast loading floppy disk drive, choose the C64. Otherwise if you prefer games with less of that beepy music and at a cheaper cost as well live in Europe, choose the ZX Spectrum.

Q: Is there a way we can experience and compare on the quality and graphics between those 8-bit computers?
A: Yes well the Life of Pixel game is like going into various Worlds of various Systems but their speed and resolution ratio won’t match as their native originals. Also you can use RetroArch or maybe the RetroPie for the Raspberry Pi to use their emulators for that.