Spectrum Hardware Index - I
Name: I-PackManufacturer: Griffin Electronics
Price: £15-20 approx.
Blurb: Input/output interface with 8 analogue and 4 digital inputs and 4 digital outputs.
Source: Magnus Loutit
Name: I2L Joystick InterfaceManufacturer: Interactive Instruments Ltd.
Price: £14.95
Blurb: Standard Kempston compat. joystick interface.
Source: Home Computer Weekly August 83
Name: I2L Spectrum SoundManufacturer: Interactive Instruments Ltd.
Price: £9.95
Blurb: Sound amp with speaker and Load/Save switch.
Source: Home Computer Weekly August 83
Name: Indescomp 32k Ram PackManufacturer: Indescomp
Price: £39.95
Blurb: Upgrade 16k Speccy to 48k
Source: Your Computer June 84
Name: Indescomp Domestic ControllerManufacturer: Indescomp
Price: £49.95
Blurb: None, but I assume its an interface to control electical systems by switching the power on or off.
Source: Your Computer June 84
Name: Indescomp Joystick InterfaceManufacturer: Indescomp
Price: £14.95
Info: Standard (Kempston) joystick interface.
Source: Your Computer June 84
Name: Indescomp Sound AmplifierManufacturer: Indescomp
Price: £10.95
Blurb: None.
Source: Your Computer June 84
Name: Interface 007Manufacturer: G.A. Bobker
Price: £34.95
Blurb: Back-up interface with built in joystick port.
Source: Your Sinclair May 86
Name: Interface IManufacturer: Sinclair Research Ltd
Price: £29.95 (seperate), £49.95 (with Microdrive)
Blurb: Controls up to 7 Microdrives. Built-in RS232 interface. Network up to 64 Spectrums. This, along with the Microdrive, revolutionised the way that the Spectrum worked. For the first time, Spectrum owners could experience fast access times and super-fast loading.
Source: Sinclair User Oct 83
Sinclair Interface I + MicrodriveThe following article was taken from Sinclair User - October 1983The Microdrive with the Interface 1 module has produced the biggest improvement to the Spectrum yet. It can do eveything a disk drive can do but is much cheaper and the interface contains three modules for the price of one. The interface unit controls the Microdrive and RS232 communications/printer interface and a network which allows you to talk to another 63 Spectrum users. The unit fits underneath the Spectrum and tilts it a comfortable typing angle of 20 degrees. It is fixed in place with two screws to stop any 'wobble' that might occur. On the back of the unit are 3 sockets and a duplicate of the expansion connector, so other devices can be plugged in. The RS232 interface is a standard way of connecting printers and other devices like modems which use only one wire to pass data across. Each byte is broken into eight binary bits - see the BIN function in the Spectrum manual - and sent down one bit at a time. That method of swapping information is called serial access and is used on all the Interface 1 devices, including the Microdrive. That involves timing the length of each bit and so the speed of the RS232 can be set to match the speed of the device from which you are sending or receiving data. Speeds of up to 19,200 bits per second - the baud rate - can be set easily by POKEing a number into two new system variables listed in a new manual provided. Those system variables take up another 58 bytes after the ones listed in the original manual. Sinclair has made Basic the operating system of all the devices connected to the interface, so you will have to learn to use the channels and streams information contained in the new manual along with the various extensions to Basic provided by the new ROM.
Apart from streams, the extra commands are MOVE, ERASE, FORMAT and CAT. MOVE transfers a file of information - not a program - from one device to another. CAT provides an alphabetical list of files on a Microdrive showing their names and the amount of free space in Kilobytes. Files can be protected from CAT by including CHR$(0) as the first letter in the name. As with cassette files there is no foolproof way of protecting anything on a computer. ERASE allows you to clear out the file named on the Microdrive and FORMAT allows you to wipe a Microdrive cartridge.
The Microdrive is a very simple device. It has only two moving parts - three if you include the write-protect switch. The motor and a ratchet which stops the motor reversing are the only moving parts. The tape head is fixed and two springs either side, which bring the tape to the head and not the other way round, eliminate the need for alignment of the head. It acts like a very fast continuous loop tape recorder running past the head at 30 inches per second - 16 times as fast as a normal cassette recorder.
The tape is made of 1.9mm wide, 23 micron thick video tape, which is slightly thicker than domestic home video tape. Sinclair claims that more than 5,000 operations can be done on the tape before it wears out. The tape format is in blocks of 512k bytes called sectors and if a block is faulty it is marked so that it is not used. All cartridges have at least 85k of space but the amount varies depending on the number of sectors damaged by the manufacturing process. With up to eight Microdrives connected to one Spectrum, 860k of storage can be acheived. Cartridges are available at £4.95 each.
The following review was taken from Your Computer 1983Sixteen months after they were announced the first Microdrives are jut being delivered, The price is still £50 for a drive which takes 85K tape cartridges instead of the l00K originally promised, but you can find and load a program in a few seconds. You will also need the Interface 1 before you can plug in up to eight Microdrives, but this interface gives you RS-232 and local area networks.
The Microdrive is housed in a box 90 by 85 by 40mm in size with an aperture at the front for loading the cartridge, and printed circuit board edge connections on both sides towards the rear. The right hand connector plugs via a flexible cable to the interface unit, if it is Microdrive 1 or plugs directly through a double ended socket to the next Microdrive. The drives are secured to each other by a plate underneath the housings. This should prevent the dreaded wobbles.
There are two small printed circuit boards inside which are without modification. The lower board provides the two edge connections, while the central vertical board houses a ROM and the tape head, which is used for both record and erase functions.
The mechanism is uncomplicated- The drive is generated by a rubber roller mounted directly on the end of the motor spindle. Pressure is applied by a leaf spring on the opposite side of the cartridge. The spring also maintains the cartridge position relative to the head, a very simple and highly efficient setup. My only worry would be head wear due to the abrasive action of the tape.
When the Microdrive is running, an LED indicator is lit. A warning is given not to remove the cartridge while this light is on
The cartridge is claimed to be able to handle up to 50 files and have a minimum storage capacity of 85K. The two spare cartridges supplied for the review both had 90K of storage space available when formatted,
Typical access was very fast in comparison with cassettes but, human nature being what it is, you tend to notice when it is slower than usual, It can take longer to type in the load command than to find and load a short file The storage media is an endless loop of tape. The cartridge is very small 45 by 35 by 7mm., including cover and makes the opposition's 75mm. floppies seem huge in comparison. The cartridge can he write-protected in a
similar manner to cassettes by removing a plastic tab, a piece of sticky tape with re-enable write.
I assume that before long we will be able to purchase S100 and S200's - Sinclair 200K -cartridges, In some
applications it is quantity of storage rather than speed of access that is important. It will also be necessary to
store the cartridges in a holder similar to those available for cassettes. The Sinclair hardware add-on industry
is in business again.
Sinclair only supplies one blank cartridge per Microdrive, further cartridges are supplied singly with an order form for repeat purchases. Bearing in mind Sinclair's advice on the need for back up copies, it just is not sufficient.
It is possible to use strings for filenames in the Microdrive commands and variables for the Microdrive number.
Because of the initial high cost of the cartridges, it makes sense to produce the tidy facility shown in Program 1.
Program 2 was used to test the file storage capacity of 50 files. Three points emerged from the tests:
1) Each file appears to occupy a minimum block of 512 bytes.
2) As the limit of 50 files is exceeded, file names disappear from the catalogue in an apparently random fashion,
but they still occupy space on the cartridge and are still loadable.
3) The average time taken to Save a short file in this manner is 10 seconds.
An attached Microdrive has no effect on the vast majority of commercial software. Only in one case where a
program used interrupt control was a program found not to work, and I am not sure why not. If you open a stream to the Microdrive or Net then problems will arise, but if you do not try to use the Microdrive or try to Network a program then it should make no difference whatsoever. The user is warned not to remove a cartridge while the Microdrive's LED is lit and not to switch on or off with a cartridge in the drive. This I continually forgot with no apparent mishaps to the stored data.
I think the user would be wise not to leave a cartridge in the drive for long periods of storage, the pressure roller
may take a permanent set and upset the tape transport. I would have liked a protective flap over the cartridge
entrance, not all drives will be used in a clean environment.
The ZX Interface 1 was also announced in April 1982. It was simply called the RS 232/Network interface board
and was expected to sell for £20. Since then it has been expanded and now serves three functions:
>Microdrive controller
>RS232 interface
>Local-area network
This little box of goodies is something special. There are flaws but it is still a very powerful addition to the Sinclair range of computer peripherals.
Surprisingly the two printed circuit boards in the Microdrive show no signs of modification whereas the printed
circuit board in the interface has been altered. The board contains two integrated circuits, a prototype Ferranti
LSI and an EPROM.
A Sinclair spokesperson has stated that the equipment delivered to customers will, in fact, contain proper
production devices.
The interface plugs into the Spectrum rear connector and is attached through two existing screw holes to the
underside of the Spectrum, the original screws may be discarded. A duplicate rear connector port is available
on the interface as are the two 3.5mm, network sockets and the nine-pin d-shell connector for the RS-232
printer/peripheral interface.
The Microdrive plugs into the exposed printed circuit board edge connector at the side through a flexible cable.
The whole assembly is rigid and now the keyboard has been tilted, feels much easier to use.
The interface unit acting as the Microdrive controller, expands Sinclair Basic to include elementary file handling
and communications commands.
The commands are created by paging the 'new’ RQM which creates an additional set of system variables. It
looks from an cursory glance, that it is possible to re-vector the input - output routines used in both the
Microdrive and Network channels.
The commands become a bit of a chore to handle after a while and you are soon driven to looking at
producing your own simple operating systems.
The RS232 interface, which operates over a range of 5O to 19.2K baud with no parity, 8-bit character and two
stop bits, should cover just about all but split-speed operation There are two modes of operation.
The t channel is normally used for listings, the control codes are not sent except for 13 -carriage return - and
the token codes are expanded. There is no graphic capability. These characters are replaced by code 63 (?).
The b channel sends the full 8 bit code and is used to send control codes to printers etc.
I can not recall ever having said that something from Sinclair was expensive, but £15 for an interface lead is a
bit steep.
The ZX Net - local area network -promises to be a very powerful tool. The network is set up by simply joining
two Spectrum interfaces together with the 10ft. long net lead. The manual reveals a network operating at l00K
baud with handshaking between two attached devices. Up to 64 Spectrums can go on the net.
Print station facility
There is also a broadcast facility to download information to anybody listening on the net. This would permit a
teacher to broadcast a program to the whole class at once.
Other uses include the ability to set up a print station to service all the Spectrums on the net. Perhaps when
Sinclair has managed to clone a few interfaces these properties can be evaluated.
The manual falls short of the usual high Sinclair standard due, in part, to the fact that it is not a derivative of an
earlier work. Everything appears to be there but I think some of the text needs presenting in a much simpler form.
The demo tape contains a print server program, untested, and a poor-man's Horizons tape-a-data base-program
which provides the meaning of the Microdrive commands from a database at what can only be described as
slow, I was not impressed.
PROGRAM 1
10 DATA ":REM files for deletion
20 DATA ‘zxc’
30 RESTORE
40 READ a$: IF a$ = ‘zxc’ THEN GOTO 70
50 ERASE ‘m’;1;a$
60 GOTO 40
70 CAT #3;1: STOP
PROGRAM 2
10 LET a$=’Kate’
20 LET d = 49
30 LET b$ = a$: LET a$ = a$ + CHR$ (d)
40 SAVE *’m’;1;a$
50 LET a$ = b$
60 LET d = d + 1
70 IF d = 11- THEN CAT #3;1: STOP
80 GOTO 30
Name: Interface IIManufacturer: Sinclair Research Ltd
Price: £19.05
Blurb: Rom cartridge interface with twin joystick ports. Sinclair's second interface did not take off like the first one. This ROM interface was produced to try and keep up with the consoles. Instant loading ROM cartridges were produced for the interface, liecenced by Sinclair. Only 10 titles were available (to my knowledge), they were; Planetoids(Psion), Space Raiders(Psion), Backgammon(Psion), Pssst(Ultimate), Cookie(Ultimate), Jetpac(Ultimate), Transam(Ultimate),Hungry Horrace(Melbourne House), Horrace & The Spiders(Melbourne House), Chess(Psion).
Source: Sinclair User Dec 83
Sinclair Interface IIThe following articles were taken from Sinclair User - December 1983NEWS
Hard on the heels of the Microdrive, Sinclair Research launched its interface 2 at the end of September. Billed as a peripheral for beginners and experts, it costs £19.95 and allows Spectrum owners to load cartridge software and use any joystick with a nine way D plug. At £14.95, the cartridges are not cheap but Sinclair Research claims they are fast and easy to load. Because the whole program is stored on the cartridge, leaving the computer RAM unused, any program will run on a 16k machine even if it was written originally for 48k.
The cartridges already available include games like Space Raiders, Cookie, Hungry Horace and Jetpac, as well as Chess and Backgammon. True to form, Sinclair Research is offering the Interface 2 for sale by mail order only in the early stages. "The response has been good so far," says a company spokesman, "but it is too early
to say how sales will develop. We cannot predict when Interface 2 will be available in the shops."
REVIEW
Sinclair has just announced the Interface 2, which has followed the Interface 1 within a few weeks.Interface 2 provides two joystick sockets, which take standard Atari joysticks and a ROM cartridge slot. The joystick ports are non-standard, as the only software to work with them is from Sinclair or Psion.
They operate the number keys only and each joystick operates the first or last set of numbers. Despite the advertisements there is no software built into Interface 2 - only a ULA to act as a port for the joysticks. The ROM cartridge socket is also a disappointment, as it provides no special switching to page ROM's in and out. The cartridge has all 16 address lines and eight data lines on it but, because of the way Sinclair designed the Spectrum, none of the internal memory can be switched off, so the only programs which can be provided can be 16k long versions which will replace the Basic ROM.
They are available by turning-off the power, plugging in the cartridge and turning on the power. The games then auto-start. An interesting point is that Sinclair has saved money by having the bare silicon chip wired direct to the PCB instead of mounting inside the normal IC casing. A printer connection is provided at the back of the unit to run the Sinclair printer only. That is because none of the other connections is connected. It would seem that Sinclair has produced its last peripheral for the Spectrum.
At £19.9 for Interface 2 and £14.95 for each ROM cartridge, they may not be in great demand unnless the price is reduced dramatically. The joysticksare also out of step with software manufacturers who program games to work with the Kempston-type joystick interfaces. Sinclair Research is the only company selling Interface 2.
The following review was taken from Personel Computer News October 1983Plug in and go . . .
Instantaneous loadings now a reality for Spectrum owners, with the release of Interface 2, which provides a joystick interface and ROM cartridge port for the machine.
Its arrival comes as something of a surprise - it was launched quietly in late September, bang on schedule, and users waiting for the Microdrives, courtesy of Interface 1 are currently being invited to buy Interface 2 before they've even had so much as a sniff of Interface 1.
Stocks of the new interface are apparently large enough for it to be readily available, although Microdrives are still in very short supply.
Interface 2 plugs neatly into the back of the Spectrum - or, for the lucky few, into the back of Interface 1 - and provides two major advantages for the machine. First, ROM cartridges can be used, so all you need do is power up for your program to be ready and loaded, and second, it will accept two standard Atari-type D-plug joysticks.
Sinclair Research emphasises that these can be any type of joystick with a 9-way D-plug, and that, as the necessary software is built into Interface 2, the joysticks will work with cassette-loaded programs as well as ROM cartridges. Ten of the most popular Spectrum games are already available on cartridge.
Interface 2 is currently being sold by mail order for £19.95, and the ROM cartridges are selling for £14.95 - cheap for what they are, but still something of a blow for those used to cheap games tapes.
The Spectrum was initially conceived by Sinclair as a low-cost hobbyists micro - it did the job it set out to do well, at a very competitive price. But it was still something of a bare bones machine - many of the facilities needed to communicate adequately with the outside world were left out of the design. Users were therefore left with just the cassette interface, and with a cheap, but poor quality, printer.
Bit by bit, companies like Kempston filled the gap - it became possible to use joysticks and decent printers, although there were still compatibility problems. Not all games would operate with a given joystick. and vice versa. Therefore, although some excellent games have been produced for the Spectrum, it hasn't always been possible to play them the way they should be played. And if you were reduced to playing through the keyboard alone, you'd have even more problems because of the poor response from the cut-price keys.
Construction
With Interface 2, these problems are starting to fade. The device itself is finished in the standard Sinclair Model T black, is slightly wider than the Spectrum's edge connector, and slots tidily into said connector. The ROM cartridge itself slots into a slightly oval socket, which is protected by a sort of hatch affair, and the joystick ports are situated to the left of this.
It is a prime example of the growing petite-ness of Sinclair Research products.
But in operation, it's more than just a pretty case. Setting aside for the moment the ROM cartridge facility, which will allow you to load programs which would otherwise be simply too big for the Spectrum, the joystick interface alone promises to give the market a thorough shaking up, for a number of reasons.
First, there is the advantage of standardisation. The Kempston set-up had already gone some way to achieving this, like Interface 2, the Kempston interface plugs into the edge connector, and uses standard D-plug joysticks. and the com-pany has been having some considerable success in persuading software producers to include joystick code routines in their games programs.
But this has in no way been a universal solution to the problem. Many of the Spectrum owners most willing to spend money on a joystick interface must already be confirmed games addicts, and so will have at least a handful of games which were, until now, incompatible with joysticks of any description.
You could use the Pickard Joystick Controller, which is wired up in such a way that it fools the computer into thinking that you are sending it the key codes it expects, but it is a fiddly operation to fit, and is not particularly warranty-friendly.
Interface 2 gets round this rather stylishly, and simply because it comes from the machine's manufacturer, it is assured of the position of the industry standard.
Sinclair hasn't made the support bracket, featured on the Interface I part of the package. This bracket screws on to both the Spectrum case and interface 1 to form a solid connection with the Spectrum board and reduces the dreaded RAM-wobble problem prevalent on the ZX81.
The connection has a tendency to wear down leading to frequent crashes and the omission here is particularly unfortunate considering the unavoidable amount of stress and strain likely to be placed on the Interface 2 as cartridges and joysticks are plugged in and out.
Visually, the nicest thing about the product is the cartridge itself. True to form, Sinclair has done a marvellous miniaturisation job, producing cartridges about 1.5 x 2 x 0.3 inches.
At £14.95 Sinclair is producing some of the cheapest games cartridges on the market although they now look decidedly overpriced following Commodore's recent decision to cut its games cartridges for the Vic 20 to around the £10 mark. There was some talk from Sinclair before the launch to the effect that £16 would be the price for its cartridges although it may be that the price will come down after a few months.
Another nifty feature is the red rubber skirt which envelops and protects the cartridge connector when it is not plugged into the games port. When the cartridge is plugged in, the skirt is pulled up out of the way.
There's a hinged lid over the games port and a pair of plastic plugs to protect the joystick sockets. These are easily remov-able - and also easy to lose, although Sinclair says they can be dispensed with anyway.
In use
As with all cartridge systems the power must be off when the cartridge is inserted or removed from the port. On the Atari this restriction is made idiot-proof by the access lid to the cartridge cavity switching off the power to the computer when it is opened.
Unfortunately no such safeguards are featured with Interface 2, though the law of probability says you will commit this crime at least once during the lifetime of the system.
The accompanying literature is sketchy but adequate, telling you how to program the joysticks for you own games in Basic or machine Code.
The codes follow the top row of the keyboard: ten keys equal up, down, left, right and fire for each of two joysticks and these can be read from Basic using the IN function.
All the cartridges can be used with either a 16K or 48K Spectrum because your not using much of the RAM memory in any case. You can use the interface and joysticks with cassette games as well and, according to Sinclair the games produced over the past year already have the routines for joystick control included.
Sinclair wont commit itself to when the interface and cartridges will make an appearance in the shops alongside the cassette tapes. It will depend on demaid which so far has been encouraging.
Verdict
The Interface 2 is a neat little product. Its priced about right and Sinclair obviously hopes to make a big killing in the run-up to Christmas. It would be a much better product if the cartridges were priced at £10 instead of £15.
"According to Sinclair the number of games cartridges will increase quickly. It's likely that the introduction of the Interface split the Spectrum market up into two distinct segments - serious applications for Interface 1 and Microdrive owners and games for the Interface 2 users. In the mean time its likely that cassette games will serve as a test market for the cartridges - the best selling games will obviously be 'moved across' first.
At the moment there are ten games available on cartridge. These are Space Raiders, Planetoids, Hungry Horace, Horace and the Spiders, Chess, Backgam-mon. Psst, Jet Pac, Cookie and Tranz Am."
Name: Interface III
Manufacturer: Evesham Micro Centre
Price: £39.95
Blurb: Transfers every program to microdrive. Snapshot anything in memory and dump to drive.
Source: ZX Computing Aug/Sep 85
Name: InterspecManufacturer: DCP Microdevelopments
Price: £39.95
Blurb: Multi port exspansion. Includes; 8bit TTL input, 8bit TTL output, 8 channel digital/analogue converter.
Source: ZX Computing Apr/May 83
Name: Interstate 31Manufacturer: Bud Computers Ltd.
Price: £11.95
Blurb: Joystick interface that supports the IN 31 command as used by Kempston. Also includes rapid fire and reset switch.
Source: Sinclair User Jan 85
Name: Interstate ProManufacturer: Bud Computers Ltd.
Price: £22.95
Blurb: Programmable joystick interface. Allows the unit to 'remember' settings via onboard 1k Ram. Also includes reset switch.
Source: Sinclair User Jan 85
