Intelgraph (Computer Aids) Intelligent Graphics / 80col VDU Interface board

[ortek_service]

After seeing various display solutions at the Retro Computer Festival, for small computers without built-in video controllers, it reminded me to post some info on this unusual 6502-Controlled with on-board screen-RAM display board I picked up at a rally 15yrs ago (for £1!), and had recently found it out / tried to find some info on the 'net.

Whilst mine did come with a copy of the manual - inc. schematics - it didn't mention any details of the company who made it or any particular systems it was designed to use it with.
I was only able to find one small advert for it - In Computing Today March 1983 Page 60. And a bit of a review / write-up in the Atom Forum on page 125 of Acorn User Feb 1986, where they say it was marketed by the Microtan User Group, for use with the Microtan. And that someone also had it running on an Atom (as a secondary / Graphics display?)
- Both magazines can be found as free downloads on archive sites.

It has either a parallel or serial option interface, and I don't think you'd be able to update a graphics display too often via quite-slow Asynch serial, so not really for action-games.

Attached are some (Zipped-up, as just over limit, even after I compressed these a bit pictures, and a dump of the (EP)ROM. And I'll probably try to scan the full manual sometime.

There were also some program listings with it - printed out on fanfold paper, that someone had done. But these seem to be an uncommon version of BASIC, that I've not seen before, with unusual syntax (and no spaces!) like:

10 Q=53239:LIMITQ:FORA=QTO53247:READV:POKEA,V:NEXTA

200 FORN=1TO8
210 READX(N),Y(N),Z(N)
220 NEXTN

310 OUT@P,W:USR(Q)
With hand-written notes: "OUT@11,128 for 8255"
Keep R/~W High, ~STATUS High


and another program ends:
140 MUSIC"C1D1":END

Does anyone know what computer this might be from?
- There are some Commodore-PET style graphics symbols in some PRINT statements, but that doesn't seem to support OUT@ or MUSIC !

[ScottishColin]

Intelgraph gets a small mention here on pages 24-26.

http://www.microtan.ukpc.net/MW26.PDF

Also here from page 8 onwards:

http://www.microtan.ukpc.net/MMM.PDF

nd here Page 26 onwards:

http://www.microtan.ukpc.net/Tandoc2.PDF

Hope this helps.

Colin.

[ScottishColin]

More here p32:

https://archive.org/details/iugn-03-04/page/31/mode/2up

And a PCW advert here on page 296.

https://archive.org/details/Personal...e/296/mode/2up

Colin.

[cmjones01]

That BASIC variant is odd. ORIC BASIC has a MUSIC keyword, but its syntax is different. in any case, the ORIC is a 6502 machine so wouldn't have an OUT keyword because it has no separate I/O address space. The PLAY command to be found on the IBM PCjr uses what looks like a similar syntax to this code, but it's called PLAY, not MUSIC.

Chris

[cmjones01]

Update: thinking further, might the language be one of the BASIC variants used with the Sharp MZ series of computers? That program looks like it's expressing music in MML (https://en.wikipedia.org/wiki/Music_Macro_Language) which is supported by the MUSIC statement on those systems. The LIMIT keyword also occurs in Sharp BASIC:
https://www.sharpmz.no/articles/prog...-instructions/

Chris

[ortek_service]

Thanks everyone, for the info.
As it happens, I actually have a Sharp MZ-711? (and maybe also still have an MZ-80?). I picked-up a couple of decades ago. But I don't think I ever had these running (Might have needed a non-standard video cable for MZ-700 series?)

However, I wouldn't have expected these to require an additional video board - Maybe more for those handheld Casio / Tandy TRS80 Pocket Computer, but I wouldn't expect those to have much in the way of sound generation. .
The complete lack of spaces in these BASIC programs, does suggest rather limited user RAM, with non tokenised storage, and so trying to save every space byte they could.

The Microtan did seem to be the main platform for using this card with, and maybe has some similar basic to their later Oric. But I don't recall these ever having much in the way of sound (I did have one a long time ago, that I picked up the bits separately and rebuilt it re-fitting the odd logic IC that had been taken from it. But someone sold it for me, as even 20yrs ago these were fetching rather high prices for what was in these although I did have the proper orange case and keyboard, whereas I only saw the cards at the RCF)

t's also possible that the programs have nothing to do with this card - one seems to be for controlling some 3-axis machine, and they just used these printouts as scrap paper to write info about controlling this video card.

[Mark1960]

This is quite a good site for microtan,

http://www.microtan.ukpc.net/pageProducts.html#VIDEO

http://www.microtan.ukpc.net/index.html

I have been studying various schematics for a few days, trying to plan getting my old microtan running and making a backplane to replace the hand wired one. Considering including the paging circuit of the original microtan motherboard.

[Timbucus]

Interesting card 512x256 graphics! Always remember the Microtan adverts thinking maybe that one...

[ortek_service]

Yes, 512x256 was quite hi-res back then (Schematics Oct'82 / 'Traced' / signed-off Apr'83 and most-recent IC date-codes on my Iss.2 board suggest built in late 1983). And did give 80x25 characters (6x8/9? pixels) in text mode with full 16KB Display-RAM. But it doesn't appear to have any colour options, so monochrome only.

Whereas back then, a Beeb gave you 320x256 / 80x25 text, but did require 20KB RAM and only 2 colours - Although you could use VDU 19 etc command to choose the actual 2 from a choice all the colours available. Or use lower-res. graphics modes to get more colours / Use Teletext (with only special Telextext) graphics mode to have 8 colours with 40 x 25 characters.

And Spectrums gave you 256x192 graphics / 32x24 text in upto 8(/16 Bright) colours, using only 16KB of RAM - But with the infamous attributes limitations. Although using YS Megabasic, you could get a more BBC-like font with 40character lines.


There were also four direct-fit graphics cards for the Microtan, from info here: http://www.microtan.ukpc.net/index.html

1. Tangerine Hi-Res 256x256 graphics - but Monochrome only / needed 3 cards for RGB

2. Mousepacket Colour 64 Character by 25 line colour teletext display, but rather low-res 128 x 75 pixel graphics (Presumably RAM-size limited)

3. TUG / later adopted by Tangerine 'Intelligent' 80/82 Video Card (Microtanic version Sep'84 dated manual) giving 40 x 25 text / 256 x 256 graphics-resolution with 8K RAM or 80 x 25 text / 512 x 256 resolution with full 16K Display-RAM - but still Mono.
This appears to be a rather-similar design to the Computer-aids Intelgraph one, also using a 6502A 2MHz control processor with its own 2KB RAM. But it does have the standard Microtan Bus connector, for easier connection via a backplane with enough slots

4. TUG's Programmable Graphics Module provides 256 x 256 graphics using up to 64 programmable 8x16 pixel 'characters', by extending existing character set beyond 32-127. So not true bit-mapped display and still only Mono.

And I presume most of these were available around the time of the Intelgraph one 1982/83
So it's surprising that the Intelgraph would have been that commonly-used

Although the orange-lid cased Micron system I used to have only had a 2-slot passive backplane (with a reset? push switch rather inconveniently placed on it, and it seems you needed to press after Power-on, according to manual), so with both the Main CPU board & TANEX Expansion Memory / cassette interface boards installed by default, you couldn't expand it any further

Surprisingly, I can't seem to find any good pictures of the Micron case / none of the insides on the 'net (I didn't have a Digital camera > 20yrs ago, when mine was sold, to take any), or any showing the cased keyboard.
I only found cased-keyboard shown in a full-page ad. for Tangerine systems on page 98 of this magazine https://worldradiohistory.com/UK/Ele...ay-1981-10.pdf
- Where there's no mention of any colour / better-graphics cards, so presumably pre-dated these.

[Pernod70]

Originally Posted by ortek_service

Whilst mine did come with a copy of the manual - inc. schematics - it didn't mention any details of the company who made it or any particular systems it was designed to use it with.

This is a great find, and thanks for the ROM dump.

I emulated the other known video cards for the Microtan in MAME a few years ago. This IntelGraph looks functionally very similar to the Video 80/82 card, even running the same firmware VBUG, though different version. Scans of the schematics and manual would be much appreciated, and likely to help emulation whenever you can.

Having been to the Retro Computer Festival last weekend I noticed the Microtan on the Binary Dinosaurs stand was using a EPROM Storage Card I'd not seen before, so have just finished emulating that, and now another VDU card to add support for, good timing!

[Pernod70]

After some more comparison of the Intelgraph and Video 80/82 boards they are functionally the same. I'd suspect the Intelgraph came first as it's a generic board that can be interfaced with any computer, whereas the Video 80/82 is specifically for the Microtan. The firmware for the Video 80/82 is VBUG V6 whereas the Intelgraph has VBUG V5.2.

I've hooked the ROM up in MAME in the Video 80/82 board, see attached screenshot, but looks like it's configured for serial. Hopefully there's something in the manual that explains the dipswitch settings to configure it for Microtan use.

[ortek_service]

Yes, these two did seem to be suspiciously rather similar, so I'd highlighted that.

My board doesn't actually have the extra serial parts fitted, so would expect it to be configured for parallel operation.

The Not-Fitted SWB is for Serial Baud Rate (SWB5..8), Stop bits (SWB-4) & Parity options (SWB1..3).

LK1 is for 20mA Loop mode Only and SWA1..8 (NF) have all to be set correctly for that mode. SKT1 (DIL8 - NF) is Tx+/- & Rx+/- 20mA loop.

Standard RS232C Serial is configured by various SWA1..8 switches, with all 7 serial lines on SKT2 (DIL16 - NF). TTL-level Serial uses different pins on SKT2 (and different SWA1..8 settings)

Parallel comms is via an 8-bit Databus on SKT3 (DIL16), with a ~STATUS input for reading Data and a ~DATA(COMMAND?) for writing data. There also a R/~W input, that you need to control with another I/O line if using I/O port mapped. For Memory-mapped operation, an external address decoder is required to produce the two ~STATUS / ~COMMAND signals, with R/~W taken off the bus. There doesn't seem to be any links required for parallel operation, and I assume the same firmware version works for Serial as well.
Although my board does have a link on SKT1 and some IC-sockets fitted that have no IC's in these.
I haven't spotted any Microtan-specific info in the manual, so far, but will scan it all if I can get a sheet-feeding scanner going.

I did get some pictures of the Microtan boards at the RCF, so will take a closer look at those to see about an EPROM storage card (Thought the TANEX board had many sockets for these, and there were two main versions)

[ortek_service]

Well I've just had a Fujitsu ScanSnap S510 duplex-scanning sheet-feeding scanner, I'd rescued from a thrown out, running after finding a suitable PSU and managing to find software and drivers online (Seems Fujitsu were just in process of ending support for it in Sep'22, so might be planning to take software (updates) from their website).
It's a slightly-older model than the S1500 I'd bought-in at work 10years ago, that has automatic ultrasonic detection for >1 page at once being (mis)fed, that proved quite handy. So I ended-up feeding the cardboard cover in separately, as some pages just after that got fed in with it the first time and so weren't scanned.
For some reason, they also upped the PSU voltage from 16V to 24V on later one, but had also changed the connector so it wouldn't fit older (but very-similar looking models).
I've always been impressed by these ScanSnap's - much faster & better quality than the v.slow & bad quality one on my HP Officejet All-in-one printer etc.

And I'm now attaching an OCR'd PDF of the Integraph's Manual (Which has a no page numbers addendum-sheet inserted between pgs 31 (end of section 4) & 32 (Start of section 5 - Assembly), that covers (VBUG) 5.21 + 6.0 Operating Systems extra commands & Terminal Emulation mode, since the older version that the manual was written for.

Also attached are the program-listings I got with it
- I've now seen that the first listing is actually nearly a line-for-line copy of the '3D' rotating object demo program in the manual (It's mainly been altered for a different host computer's BASIC language)

[Pernod70]

Originally Posted by ortek_service

And I'm now attaching an OCR'd PDF of the Integraph's Manual (Which has a no page numbers addendum-sheet inserted between pgs 31 (end of section 4) & 32 (Start of section 5 - Assembly), that covers (VBUG) 5.21 + 6.0 Operating Systems extra commands & Terminal Emulation mode, since the older version that the manual was written for.

Thanks for these, plenty of good info in there for me to work with.

[ortek_service]

Just for completeness (and to save some time finding magazines on the the 'net
- One on these from the Archive website in PDF with OCR'd text, had 'Extract pages' greyed-out in my full version of Acrobat 9 I scan-to / use for cropping & OCR-ing pdf's) - then I've attached a couple of pages with info on the Intelgraph (that I'd originally-mentioned was about the only info I could find out there).

So here's about the only advert I found for it (cropped and Image-snapshot taken - Also zipped-up in case forum compresses image .JPG too much, to display it).
And also the Acorn User Atom Forum article on mentioning using it with an Atom.

[ortek_service]

One slight puzzlement to me is that addendum sheet, in the manual that came with my board , mentions the later 5.21 as well as 6.0 versions of VBUG.
However, my board came with a VBUG 5.21 EPROM fitted - Whereas I would have thought it would have come with 6.0 if that was released when the board had originally been bought.
Unless there was any backwards-compatibility issues and couldn't just use the latest one.

In their Mar'83) advert, you had to buy the bare PCB and the 8KB VBUG EPROM together, for the quite-high price of £55 + £2.50 P&P (Although they did give you a manual, that they charged £5 + the P&Palone for)
- More than a full ZX81 kit cost?
But it didn't mention what version it was / if you could buy just the EPROM as an upgrade to previously-built boards.
And looking through the contents of the VBUG 5.21 EPROM, although that has V5.2 version in it, there's no date recorded in it even though it looks like there's quite a bit unused. It does say 'No Serial Option in one place, so not sure if a different version was required to support that or whether it was just for reporting the current config.

So I wonder when the various versions were released. - And it might be nice to get a copy of VBUG >=6.0, if that was the last version for it, to try with this.

[Mark1960]

I think vbug 6 is on this page for 80/82 video card though the images are not clearly labelled.
http://www.microtan.ukpc.net/

[ortek_service]

Originally Posted by Mark1960

I think vbug 6 is on this page for 80/82 video card though the images are not clearly labelled.
http://www.microtan.ukpc.net/

Thanks for the info. I've just had a quick look and under Firmware from the main menu:

Under Toolkits - Which seem to for use in the Microtan Host

Video 80/82 Toolkit.

Video 80/82 Toolkit Manual:
http://www.microtan.ukpc.net/Product...lkitManual.pdf
- Which I thought may also cover the 80/82 board. However this link seems to be broken, eventually going to:
https://freeola.com/errors/e.php?ec=404

VDU 80 Toolkit Image (Intel): http://www.microtan.ukpc.net/Products/VDUTKT.INT


And also lower-down, under Video Cards:

80/82 Video Card:
TUG's high resolution Video Card.
Later adopted by Tangerine giving 40 or 80 column text.

EPROMs
Main firmware for the Video 80/82 Card.
- Image: http://www.microtan.ukpc.net/Products/VDU80.INT
VBug is the operating system for Microtan's 80/82 Video Card.
VBug 1.2 is supplied for 40 Column use.
VBug 6 (PTL) is supplied for full functionality.
- VDUTKT (PTL) Image: http://www.microtan.ukpc.net/Products/VDUTKT.INT
- Which is a duplicate link-address of the Toolkit Image file. So it looks like they've made an error here ! And not sure if VDU80.INT is actually Vbug 6 (PTL), with no copy of Vbug 1.2 40col firmware.

The firmware files are all. INT and open up with display of the Intel-Hex in text only webpage, if just clicked on rather than saving link.

Vbug 1.2 seems to be quite a low version number compared to 5.2 / 6.0. And my manual seems to indicate that it automatically went to 40col mode if only 8K rather than full 16K of Screen RAM was present at boot-up. So not sure if 1.2 was a special version that permanently went to 40col (Although it would seem to be easier to just not fit / remove the 'wasted' RAM, if you didn't want that mode / I would expect there's maybe a command to change a 16K board to 40col)

[Pernod70]

Originally Posted by ortek_service

The firmware files are all. INT and open up with display of the Intel-Hex in text only webpage, if just clicked on rather than saving link.

Here's VBUG V6 (VDU80) converted to binary format. There is no known dump of VBUG V1.2.

[ortek_service]

Thanks for confirming which was the correct V6.0 firmware file.

I wonder if there was any original commented assembler source files for the Intelgraph / 80/82 firmware. Or for the Toolkit firmware, for the Microtan host side (Maybe more likely, if this was developed by the Tangerine Microtan community?)

It would save having to disassemble the 6502 binaries, and rev-eng what was going on - if not already done - if wanting to know more about exactly was going on with these.