Your Spectrum
Issue 21, December 1985 - Spectrum+ 128K
Home Contents KwikPik
Most people have heard of, and by now seen pictures of, the new 128K Speccy. But very few have ever used one. Sinclair flatly denies that there are machines in the UK (most of the design and testing work must have been done over the phone) so I packed up a YS survival kit (including a bunch of tapes, an Interface 1 and Microdrive) and set off for one of the world's shortest breaks in sunny Spain. My mission? To penetrate the top secret and heavily armed Investronica factory in Madrid.
The Spanish connection is easy to follow. Investronica is Sinclair's Spanish distributor and will soon be manufacturing its own Spectrum+s. The 128K Speccy is its idea - designed specifically to sell in Spain and Mexico. But a lot of the work on the new machine has been done by Sinclair's Metalab and there are odd machines holed up in English software houses working on 128K software. No one knows when an English version might appear, if it will at all - though I'll bet my last peseta it won't be this year. The machine I used at Investronica's research lab wasn't even a finished Spanish machine so there's little reason to suspect that an English 128 will be anything like this ...
The 128 looks very different in the pictures but it turns out to be a familiar friend - a Spectrum+ case and keyboard with '128' tippexed on the top and a huge chunk of gun metal bolted on the right hand side. It's a real heatsink and when they say 'heat' they mean heat - it's painful to the touch. There's also a separate numeric keypad which plugs into the front right of the unit. Other things have changed too; the MIC and EAR ports have been moved to the left hand side, next to the reset trigger and a combined RS232 and MIDI port using one of those QL- style phone jacks.
Round the back, there's an RGB port for a proper colour monitor. Investronica's machines were totin' BMC's QL monitor producing a display like you've never seen before. The colours are dazzling, rock steady and pin sharp. Try and stipple this and you won't get far! It's a con though - the QL needs a much higher resolution monitor than a Speccy and it's unlikely you'll bolt something this good onto yours. Investronica is also trying to figure a way to get a colour composite video signal onto the same plug. This'll let you use an El Cheapo quality monochrome screen for programming and word processing and just go for colour when you need to on a TV set.
The acid problem with the 128 is compatibility with existing software - the Spectrum's design leaves
T H E   S P E C T R U M . W I T H   N O   N A M E

The 128K Speccy hits the streets in Spain this month but we still don't know if and when we'll see it over here. Beyond the call of duty free, Max Phillips flew to Spain to try out the secret Sinclair.
nothing for you to play around with. And most programs stretch the machine to its limit - so much so that one slip and existing software just won't go on an upgraded machine. The 128 takes the tough and reliable solution even if it might be hard to get along with - it's schizophrenic.
Switch it on and it's a 128K Spectrum and it's not very compatible with your existing programs. Enter the command SPECTRUM and bang goes your 128K, bang goes your RS232/ MIDI interface, bang goes your numeric keypad and you're staring a Spectrum+ in the face. There's no way to go back and use any of the 128K features without resetting the system - no, not even from machine code.
The advantage is that the 48K mode should be 100 per cent guaranteed, no strings, genuinely compatible with all existing programs. I say should because the machine I saw wasn't - Investronica claims that because current 128s use EPROMS (and yes, the first lucky owners will get EPROM machines) then there are timing differences that stop turbo-loading tapes working and there seem to be other odd hiccups still to sort out. Still, the brute force '48K mode' method should make perfect software compatibility possible.
The expansion connector is unchanged and most add-ons will work as before in 48K mode and possibly in 128K mode. The only hitch is with add-ons that attempt to load software into RAM during power-up or reset. Sorry, since it powers up as a 128K machine, many such add-ons will be in real trouble. This may effect ROM based games but I don't think that's going to bother anyone unduly.
The disadvantage to dual modes is that you're going to need special 128K version of programs to use the new features. Simple Basic programs work fine in both modes but anything that's remotely trick won't and that includes 99 per cent of commercial products. Still, the transition has already started and there are games being given the 128K treatment (not mentioning any names, Ocean).


128K mode is something of a shock. It provides a proper intelligent screen
editor, a calculator and a sort-of enhanced ZX Basic. Numero Uno (as they kept saying) is that the single keypress keyword system has been junked. In 128K mode, you type out keywords letter-by-letter (sorry, no abbreviations allowed). Programs are entered and edited with a full screen editor - a bit like writing your programs with Tasword. You can switch back to a 'command mode' where you can enter Basic commands by pressing Cambio-Cmnd on the numeric pad (Cambio - that's Symbol Shift to you and me).
All editing really takes place using the keypad although some of the keys (like the cursor keys and delete keys) are duplicated on the main keyboard. The keypad provides - wait for it - cursor movement by character, word and line as well as jumping to the start of the previous Basic line or the end of the next. You can delete by character or by word in either direction. The editor is also pretty smart - it splits multiple statement lines up onto separate screen lines and will scroll up and down the listing as you move through it. There's no more stopping to reLIST a bit of program or hitting up arrow five times to get to the line you want. Better still, you've still got on- entry syntax checking - press Enter and the position of any mistake is highlighted. The 128 even uses a bug- shaped UDG instead of the grotty old question mark!
The Basic editor is nothing short of a dream. Any time you lose, typing out keywords in full, will quickly be saved by the time it takes to get the whole program in and working. That said, it does lack things every self-respecting screen editor should have; there's no search and replace, no copying and moving lines and so on ...
Basic programs written in 128K mode (with fully typed keywords) can be loaded in 48K mode and vice-versa and will run quite happily provided they don't do anything too tricky. You can also use the extra facilities of 128K mode to write a program and then switch with SPECTRUM with your program still intact. Well, that's the

Investronica 128K package
The Spanish 128 will be available as a complete setup with a superb BMC monitor and a serial dot-matrix printer.
128K rear view
The RGB port on the rear of the machine will also provide a composite video signal.
128K side view
The MIC and EAR ports are now on the left side along with the combined RS232/MIDI interface.

theory - I couldn't even get the demo tape to load in 128K mode. The odds are in your favour if you want to move your machine code programs across as well - provided your routines aren't too big, don't rely on the standard Spectrum ROM or step all over any of the new interface and bank-switching gear!
Once you're in command mode - you use the E command to go back to editing your program - the keypad acts as a four function calculator. It seems to use ZX Basic for its arithmetic routines and Investronica claims that it has an enormous number of calculator memories (probably Basic variables) even if there was no-one around who knew how to work them!
The other extra application is the ability to use the screen editor as a text editor. You just type, for example, E A$ and, yes, you get to edit A$. A couple of the keypad functions change here - instead of start and end of previous and next Basic statements, you can scroll up and down by screenfuls. The editor works in insert mode or overtype mode or can be set to automatically indent text - the left margin sticks wherever the cursor was when you entered S/A mode. Quite what you use this for I'm not sure. You
can also train the editor to wordwrap so that words don't get split at the ends of lines.
Although most big machines have a text editor as standard, it seems a bit out of place on the Speccy. It's not a word processor as it doesn't offer half the facilities you need and can't format the text for printing. But it could come in handy for creating data files or source code for programs in other languages and so on. Since you can specify the variable to edit, you can keep several text 'files' and programs in memory and use the calculator all at once.
128K mode Basic is good ol' ZX Basic with extensions for sound and for handling the extra memory. There's also talk that it will feature handy extras such as RENUM and DELETE but we'll have to wait and see.
Sound is very changed - for a start there's a hole where the tiny little speaker should go. Sound is now produced (in both 48K and 128K modes) through the TV speaker or through a Hi-Fi or cassette recorder connected to the MIC socket. So all existing programs are suddenly a lot noisier and you've got volume control. This means that everything from simple BEEP commands to complex sound
programs such as Tony Samuels Samsynth in YS 19 will all work a lot better!
In 128 mode, the beeper is banished forever - there's one of those jolly 8912 chips which provides three separate voices for chords, pure sound and white noise and limited envelope control. This allows you to do passable impersonations of BBC Micros and Commodore 64s although 128 Basic doesn't appear to provide complete control of the chip.


The new sound command is PLAY followed by one or more strings containing a music program in single letter instructions and numbers. For example Y sets the type of sound, O sets the octave and so on. You can embed comments inside PLAY strings to make the otherwise cryptic strings more readable. PLAY can also be used with the MIDI interface ... this is three spare pins on the RS232 port that let the 128 talk to all sorts of musical instruments, synthesisers and so on. The interface supports up to eight voices rather than the three on the built-in sound chip. In theory, programs that are written for the 8912 chip will work straight away on

anything plugged into the MIDI interface but, again, the 128 I tried refused to co-operate.
Sound has to be one of the 128's radical improvements. Although Speccy games lead the world, their sound always has to be taken with a pinch of imagination. Even a simple 128 mode conversion can include 8912 support and the transformation will be dramatic. The best thing I saw a 128 do was the machine sitting next to mine and it did it for the entire time I was in the building. Hooked to a fancy Casio organ and in turn to a Hi-Fi, it ran through a superb rendition of five popular tunes repeatedly. And it did it without reaching for its microdrive - all five tunes were loaded into memory and switched between automatically. It's an English demo program so expect to hear of it soon ...
Investronica stalled on the exact details of the bank-switched memory system - as it did on the bulk of technical details. Its reason is that things might be changing dramatically - they sure are in for a busy month! The basic principles are 128K RAM divided up into 16K pages, any four of which can appear at any position in the Z80's 64K addressing space. There's 32K ROM on board (EPROMS on early machines) divided into 16K for the original Spectrum ROM and 16K for the 128K mode ROM. One source suggests that either the top or bottom half of the ROM is paged into the first 16K of the Z80's address space. However, Investronica detailed a much more sophisticated and versatile idea - on power-up, reset or entering SPECTRUM, the appropriate 16K of code is copied from ROM into a 16K RAM page and that page is then switched into 0-16K of the memory map.
This first page of memory is then, apparently, write-protected so that it appears to be ROM. If this turns out to be the case, it should be possible to pull all sorts of lunatic stunts such as altering ZX Basic and then switching to 48K mode. If the software control is there, you should also be able to dispense with the ROM altogether and run pure 64K programs. What a shame video memory still starts at location 16384 - you still can't persuade a Speccy to run the standard CP/M operating system without extra hardware. Rats!
In 48K mode, three RAM pages are switched in above the page pretending to be the 16K ROM. Who cares which pages they are as once they're in, the banking is disabled and you can't switch to any of the other pages. There's nothing a program can do, however wayward, to get back to 128K mode.
In 128K mode, three pages are switched in to give you a normal 48K system but the remaining 64K (four pages) are available by the bank- switching mechanism. This gives you around 104K free for Basic programs
and their data and a maximum of around 120K for pure machine code. Remember that the system variables and screen area are still going to steal around 8K of the space.


The extra memory appears to be supported from Basic by the rather crude solution of a RAM disk - using the commands LOAD! and SAVE! So long programs have to be split into chunks and called from the RAM disk as needed. Note that this is non- standard syntax in terms of Interface 1 commands - you'd expect some new channels but, of course, not every 128 owner will have an Interface 1 and there isn't room to put some or all of the Interface 1 stuff in the 16K ROM in the machine. However, it should be possible to do your own bank- switching using IN, OUT, PEEK and POKE if you need greater control. Machine code programs can, of course, make the entire 104K (or 120K if the ROM really can be replaced with RAM) appear as one continuous chunk.
The 128's RS232 port is the same as the Interface 1's port - Investronica says it's pin compatible but since the pins are a different shape, you'll need a new cable anyway! It's a shame that it's not an enhanced version of the port as anyone who's tried it will know that you can die trying to make it do full- duplex (transmit and receive data at the same time). This makes it fine for printers and micro-to-micro links but modems will still be a pain in the neck. If you've got an Interface 1 attached, the built-in RS232 remains what Investronica calls 'the primary device'. Quite how your programs address the Interface 1 RS232 or how current programs will react to the new port remains to be seen ...
As for pricing, Investronica sells old 48K Spectrums for 27000 pesetas (around £122) and Spectrum+s for 36000 pesetas (£164). It's price of 50000 pesetas for the new 128K machine works out at £230 over here which is probably no guide at all.
So how good is the 128? The extra memory and improved sound opens up all sorts of possibilities for new software. But the 128 is a bit messy since it doesn't incorporate or build-on the facilities provided by the Interface 1. Neither does it (apparently) provide any serious enhancements to the ageing ZX Basic other than a bare minimum of support for the new hardware features.
It will be interesting to see how the machine changes when it makes it to an English version. Certainly, I could think of things I'd rather have than a simple (and rather slow) text editor. And who needs a four-function calculator when all you need to do is stick the keyword PRINT before the calculations? OK Sinclair, we're interested and we know you can do it ... why are we waiting?


Here's how the Spanish 128K Spectrum looks at the moment. Be warned, all details subject to change on production and UK versions!
Z80A, 3.5 Mhz.
128K RAM in 16K pages.
32K ROM, 16K original Spectrum ROM for 48K mode, 16K for new 128K mode.
As Spectrum.
As Spectrum with extra Extended mode/ Symbol-shift keys for Spanish characters. Separate numeric keypad for use in 128K mode. Provides calculator and screen editing keys.
8912 sound chip, 3 voices, pure sound and white noise. New PLAY command provides control from Basic. Sound is played through TV - there is no internal speaker.
ZX Basic, Text Editor, Calculator, Basic screen editor.
As Spectrum in 48K mode. In 128K mode, keywords must be typed in full and there are extensions for Ram disk drive (LOAD!, SAVE!, CAT!) and PLAY.
RS232, MIDI music interface, RGB monitor, Composite Video monitor. MIC, EAR and expansion connector as Spectrum.
50000 pesetas in Spain.
UK price £180?
128K keypad
The keypad is standard and provides editing keys and a calculator.
Home Contents KwikPik