Miscellaneous Operating Systems/Hardware

I'm wondering why it has some 3.5 floppy disks included when the pics only show a 5.25 drive. There may be more included hopefully.

I do though have (on 3.5) a full boxed set of Interactive UNIX 2.2 with 50 odd manuals.

So picked up my £8 IBM XT tonight, and I have to say, thank god it was only £8 otherwise I'd have turned back, Walsall has to be THE worst place in the world to drive, even my SAT NAV gave up and told me to go fsck myself!!

Anyway, got it home, it's boxed in original box even with the foam. But excitement lead to disappointment when I realized the monitor is SVGA and the XT only has 9 pin output.
It does have some interesting cards in though, especially the Asynchronous Communications card, the manual supplied looks like it does some interesting things (the manuals are pretty cool).

So I'm sat here think, well, it will just have to go in the loft..... BUT THEN!!!

I suddenly remembered, a small boot load of stuff from my ex house arriving some months back via my daughter. That contained the monitor for my SAMSUNG 8088 9 PIN monochrome!

Back on track, tomorrow, I'll be extracting said monitor from loft, attaching big fat keyboard (another thing that didn't come with it) and booting the old boy up!!

It also has DESKVIEW by quaterdek..

On that note I've just won 2 INDIGOs'

better check what the graphics actually is, 9-pin could be MGA, CGA, EGA, or Hercules, all different and seldom compatible.
If there is also a composite RCA port (for a television) it's CGA. CGA also has a cool light pen port.
Conversion of CGA/EGA to regular VGA-style video is simple and there are very cheap adapters out there, but not all monitors can sync at the lower frequencies used

robespierre wrote: better check what the graphics actually is, 9-pin could be MGA, CGA, EGA, or Hercules, all different and seldom compatible.
If there is also a composite RCA port (for a television) it's CGA. CGA also has a cool light pen port.
Conversion of CGA/EGA to regular VGA-style video is simple and there are very cheap adapters out there, but not all monitors can sync at the lower frequencies used

I'll bear that in mind Robespierre, thanks.
It has no RCA port, other wise I may have been looking at hooking it through one of my video type converters. But fingers crossed.. it will work. I recon the source machine is the same era, so I'm hopeful (pre-anything half decent).

If it doesn't work, then well foo bar! I'll no doubt buy a monitor that works and my £8 machine will end up costing thousands... NOT!

my WoodyBox has a similar problem: the CRT tube is 9-pin
and 9-pin could be { MGA, CGA, EGA, … }: all different and seldom compatible .

Looking at the cable I understood my CRT tube is CGA,
then I bought 3 vintage video boards from ebay,
and … none of them worked ='(
I mean, all of these video boards are combo VGA-CGA, and the VGA was not working too.

VGA: NOT working
CGA: NOT working

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ pinout differences ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Enhanced Graphics Adapter (EGA)

• pin1 GND
• pin2 Red_2, TTL
• pin3 Red_1, TTL
• pin4 Green_1, TTL
• pin5 Blue_1, TTL
• pin6 Green_2, TTL
• pin7 Blue_2, TTL
• pin8 Freq_H @ 15,7 / 21,8 kHz
• pin9 Freq_V @ 60 Hz

Color Graphics Adapter (CGA)

• pin1 GND
• pin2 GND
• pin3 Red, TTL
• pin4 Green, TTL
• pin5 Blue, TTL
• pin6 Intensity, TTL
• pin7 -
• pin8 Freq_H @ 15,75 kHz
• pin9 Freq_V @ 60 Hz

Monochrome Display Adapter (MDA)

• pin1 GND
• pin2 GND
• pin3 -
• pin4 -
• pin5 -
• pin6 Intensity, TTL
• pin7 Video, TTL
• pin8 Freq_H @ 18,432kHz
• pin9 Freq_V @ 50 Hz

the MDA Catode Ray Tube Controller is based on Motorola MC6845
which looks "almost" similar to MC6800

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ pinout differences ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~




last chance, a final opportunity to achieve something: the fourth video board bought on ebay!
I got it one week ago, I received yesterday and ....... strange, but true ...... it worked X_____X

VGA: working
CGA: working

oh, so lucky I am, just only on the fourth try




In your case ..You could, eventually, buy a combo (CGA-VGA) video card like mine, recycling a VGA monitor.
I do not know if the XT BIOS will work.

5th time lucky eh ive.. well. I may be coming after you for those that don't work should my loft residing monitor fails.

One thing, I know XT etc are big machines, but the box it came in FFS!! I don't know where I will store it!

ivelegacy:
That was just a recitation of the common video cards for a PC XT :)
There are of course other kinds of video that could be found with 9 pin connectors. The relevant factors are
1. video signal level, VGA (and most contemporary "analog RGB") uses 1Vp-p, but CGA and EGA along with most earlier standards use TTL levels (between 1.4 and 5 Vp-p).
2. Sync level and polarity
3. horizontal scan frequency and #lines
4. vertical scan frequency and refresh rate
5. for accurate color, you need to know the color data format. Digital RGB may or may not have Intensity control (RGBI), EGA uses weird 2-signals per primary color, and some systems use YUV to make life difficult.
When you're especially lucky, the monitor may be designed for multiple formats and all you need to do is flip a switch.

uunix wrote: If it doesn't work, then well foo bar! I'll no doubt buy a monitor that works ...

I could very well be mistooken but I think a Zenith ZCM-1492 will work with CGA / EGA. That was the cool monitor at one time.

@robespierre
my CRT tube was pulled out from an old " transportable PC ", this implies the interface was within the range { CGA, EGA, MDA }

unfortunately I have just the CRT tube with its electronic, I do not have the rest of that big-iron
(which ohh, it was 8Kg, can you really call it " transportable " X_____X ?)

I do not know about polarity differences within { CGA, EGA, MDA, VGA }, I just know something about VGA timing & signals

now I have learnt a few new things

- ebay hates me, (I have ordered the same video board for 4 times) but the forth try is lucky ( dead, dead, dead, working )
- the CRT tube of my WoodyBox is CGA
- it is not dead, it's working, greatest information

oh, good, so I have a good working set which I can analyze with my DSO and LA in order to fine tune the timing module of the VDU I have already designed for my VDU. The Video Display Unit I am cooking in VHDL looks similar to the MC6845 used in MDA.

Monitor is RCA.. giving up for the moment but will look out for a cheap IBM monitor over the course. It's all going in the loft now.

And in 20 years I'll post back with news of booting it up.

oh, so it's good for C64/C128/Amiga, I guess

I bought the PSOne's LCD (portable LCD for the Sony PlayStation One), just because it's RCA and I wanted to play with a Yamaha V9958 chip, which is the Video Display Processor (RCA output, plus a built in dynamic memory controller) used by home-computers like the MSX.

It's a funny chip, and pretty documented with a lot of examples (real usage, grabbed from games) in Z80 assembly.

You're exactly right and informative on this.. BUT IT DOESN'T FIT THE FSKING PC!! SO IT'S GOING IN THE LOFT!!

um, oh, wait a femtoSec, what about the hypothesis about putting a combo VGA-CGA video board on your XT mobo ?
is it a good thing (will work) or a bad thing (will never work) ?

mine is ISA/16 and it works on AT and ATX mobo, but I do not know about your XT mobo
just my 50 cents, buddy, to save it from the loft

uunix wrote: BUT IT DOESN'T FIT THE FSKING PC!! SO IT'S GOING IN THE LOFT!!

Have you calculated the load-bearing capabilitiy of that loft recently ? Maybe take a few moments to look at the fasteners, check for dry rot, and so on ?

Anyway.. I have brought home a Pentium 4 with a rather cool case.. badged CyberMaXX

The Tavern drive is picked on this and I'm thinking I may put OS/2 on it, maybe server and see if I can set up an NIS domain or similar for it.

Fans a bit noisy, but I'll get that replaced, might swap out the o2 for it since I bet the KVM will work fine, but I was having a bit of fun with smoke and the indy cam ported through the o2 last night.. so I may have forgiven it.

Still haven't got the Sound Blaster working in the original 586 project.

And my wife to be has bought me a new lamp for the room since I've been without light for a month now.. how nice.

I am working as broker, buddy, make an offer to us (my group) in PM. From SB16, AWE32 to AWE64-Glold , the choice is still available, but I haven't tested them with DOS yet (because I was with the need to have a damn ISA mobo (1)), while I have found two floppies for the GalaxySound Card, plus a copy of KK , which is an amazing dos game and it uses the SB, so it's good as testbench. The AWE64G is currently on ebay now, my friend is asking 50 euro + shipping because it's a brand new card with manuals and box and other crap (midi cable? who does need it? microphone? oh well), probably other SB cards can go away for 10-20 euro, just because they really are second hand and without manuals. If you want the whole lot, I can try to persuade him or them to fill out a special price, something like 30 euro for the whole, not including the the AWE64G, or something like 60 euro for the whole-lot. Plus shipping, which ... if you do not have a better solution will be something like 20 euro to UK. Sorry, I haven't a better solution about that (netherland has better shipping servide, I am really impressed, cheap/fast/excellent service).

(1) oh, but yesterday I also got the dead corpse of an IBM Aptiva/486 , which is dead but it works in the definition of "working dead" ("walking dead"? oh well the PSU is really funny, sometime it works, sometime it does not), but ignoring all the voodoo that is required to keep the zombie under my control, this means I finally got a PC with an ISA bus !!!! Where to put a sound blaster card in order to test it with DOS! I have been looking for weeks, and on the 5th try I got the zombie, how lucky I am.

Thanks for the offer legacy.. I have another 8 sound cards to go through yet, and I suspect non are faulty, it is in fact my incompetence to actually install the correct driver and time travel back to the 90s when this kind of thing was second nature to me.

I am a god!! SoundBlaster working in project 1...
Actually.. not sure what I have done in the long haul.. but moving the card to another isa slot worked this time.

Now project 2.. OS/2

I guess that against all the nonsense in choices made by vendors abut ISA16 (like the WFT in the IRQ, DMA assignment), only the strong black voodoo can achieve success

so, well done, buddy!