Hi,

If you have 2 boards, the CGA with the 4.77 machine and EGA for the turbo XT.
EGA games like the sierra games, lucas art games, grand prix circuit…. work well Lemmings and prince of persia are slow.
MFM disk are difficult to find working, so XT-IDE with DOS 3.31 or DOS 5.0 if you have more than 640Kb of memory.
There are too few games for 4.77MHz machine using adlib. Bubble bobble works fine, space quest 3 is quite slow.
There is also my mod player of course, but be careful, SB20. is really noisy.

FreddyV wrote on 2020-02-03, 14:52:

Hi, […]
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Hi,

If you have 2 boards, the CGA with the 4.77 machine and EGA for the turbo XT.
EGA games like the sierra games, lucas art games, grand prix circuit…. work well Lemmings and prince of persia are slow.
MFM disk are difficult to find working, so XT-IDE with DOS 3.31 or DOS 5.0 if you have more than 640Kb of memory.
There are too few games for 4.77MHz machine using adlib. Bubble bobble works fine, space quest 3 is quite slow.
There is also my mod player of course, but be careful, SB20. is really noisy.

Hi,

Thanks for your reply - forgot to say that I'm going to keep just one kind of machine per CPU family (one 8088, one 286, and so on) because of space constraints and as such I'll have to make a decision between the two boards 🙁

I suppose that having a Turbo XT with EGA will overlap with having a dedicated 286 machine? If a given title runs better on a 286, I'll definitely play it on the 286 - the XT will be strictly for stuff that because of timing issues or various quirks should be played only on a 4.77 MHz.

I've found a working 20MB MFM disk, not sure how long it will keep working though... I suppose I'll grab a XT-IDE PCB and build one.
Any advantage on getting a SCSI card? I know that SCSI keeps CPU cycles free on newer machines (because of DMA, I think?) but I'm not sure if that applies to a 8088. I mean, if SCSI gives the same exact speed and performance as an XT-IDE, I guess I'll go with XT-IDE and a Compact Flash. If SCSI is marginally faster, I might think of buying it.

DOS 3.31 sounds like a good option - I like the idea of having different DOS versions on different machines.

If the SB2.0 is wasted on a 8088 I could keep it for the 286 and just build an Adlib clone for the XT. I still haven't tested it, so I hope it's NOT that noisy 😁

Thanks!

You should check if you can reduce the speed of the XT card.

The 286 works fine with VGA,

A SB inside a XT is wasted, if combined with VGA even more.
Also Adlib Games sometimes struggle even with 9.54Mhz, at least if they try to play Samples over Adlib.

I would recommend SN76489 and OPL2 Sound for best coverage 😁

matze79 wrote on 2020-02-03, 18:49:

A SB inside a XT is wasted, if combined with VGA even more.
Also Adlib Games sometimes struggle even with 9.54Mhz, at least if they try to play Samples over Adlib.

I would recommend SN76489 and OPL2 Sound for best coverage 😁

Hi,

I don't agree totally: As Adlib cards are expensive, you can have cards with OPL2 and SB Compatible at half the price.

But if we have only one card and a 286, of course, go to put it in the 286.

I would make the 286 an EGA/MPU/SB2.0 machine and keep the XT with CGA and adlib clone - these are the main components anything beyond that is your preference/convenience but I would try and install network cards in both so you can have easy transfers to the system. Obviously a xt-ide card or hd-floppy controller will help on the xt system but not required if you have any kind of working hdd setup and a nic installed.

I see no reason why would one torture himself to use a CGA on an XT instead of a VGA. Ebay is full of XT motherboards, HDDs with controllers and very cheap SB compatible sound cards (they cost around $18 incl. shipping)

When I built an 8088 a couple of years back, essentially I really only purchased a Motherboard & a clone CGA Graphics card, as all the rest of the parts were taken from the scrap of an old dead 8088 I still had in storage.

As such for storage I went with an MFM HDD, as that's what I had easily available. If you don't already have a working MFM drive then it's probably pointless trying to source one when there are easier options available. I'd also highly recommend XT-IDE. I flashed an EPROM with it and stuck it on a 3Com 3C509B - a 16-bit ISA network card that works fine in an 8-bit slot and even has a modern patched DOS TSR for an 8088 CPU.

Regarding graphics - when I built my 8088, the goal was indeed CGA only so I would recommend that. I leave EGA and above for my 286 build instead (which has a VGA card actually). Plus with a CGA card you have the option of playing games that support the Composite Colour Artifact mode, which is precisely what I was looking for with my build.

As for floppy drive, I do have a 5.25" floppy drive but I used that in my 286 instead - primarily because my XT is currently limited to 256KB RAM whilst the 286 has 1MB so will get more use out of that drive. I put a bog standard 1.44MB drive into my XT build, where it works happily in 720KB mode. Not that it gets used much. Other than using it initially to install DOS onto the HDD, I find the XT-IDE ROM with it's Serial Floppy functionality is much easier. Sharing a floppy image from another PC over Serial to my XT is so much better than having to rely on writing disks. It's a little slower than a real floppy disk, but not painfully.

I never bothered with a Sound Card for either my 8088 or 286 builds. Sound on a 286 starts to make sense, but for an 8088 it would be rather under utilised.

A Sound Blaster or compatible card is still much better than a PWM PC speaker! Many games support it even on XT. NTSC artifacts are hardly used since back then CGA was used mainly with RGB monitors, not with NTSC color TV sets that hardly could display 80 columns text.

georgel wrote on 2020-02-07, 12:27:

NTSC artifacts are hardly used since back then CGA was used mainly with RGB monitors, not with NTSC color TV sets that hardly could display 80 columns text.

There were a few games that did support it and some very good well known ones at that. It's not vital, but it is nice to have.

Thanks for your replies, everyone!

I do have a bunch of OPL2 chips bought from China - I suppose I could build myself an Adlib clone and put the SB2.0 in the 286. In the meantime I'll probably use one of the bunch of soundcards I've got laying around that work in an 8-bit bus.

I looked into Tandy 3-Sound, it looks interesting. I suppose I'll purchase a card. Are there any difference between Matze's TNDY and Lo-tech's card?

A Covox speech thing might be good as well for an 8088 I guess or is that more of a 286-era thing?

I've also managed to get a nice 160MB SCSI drive for cheap. I guess at this point I'll also get a MFM disk for the mere fact that I've already got a controller for it.

Still undecided if I need a real 360k drive or not, they're as rare as hen's teeth around here 🙁 The Gotek works well enough, but I would like to somehow use some of the boatload of 5.25" DD disks I've managed to scrape up during the years (most of them will probably go towards C64 use anyway). I've heard around that the Teac GFRs might be modded for true 360k mode? I've got two of them laying around, I suppose I might stick one of each in my 8088 and the 286 and only use 3.5" floppy drives in the 386.

Also still utterly confused about all those XT-IDE revisions and variants. Since I'm in Europe the cheapest way would probably be to order it from Lo-tech, but I can see they "only" have revision 3, while others are on revision 4.1. From what I gathered from Glitch Works, the big change in 4.0 is a fixed race condition with a newish add-on. Any other reason I shouldn't get a 3.0?

As for the graphics, I think I'm gonna go the CGA route otherwise I wouldn't have much differentiation between the 8088 system and the 286 and one of the two would end up being neglected in favour of the other. By having different graphic systems, I'd end up playing different games on either system. Also very interested in those composite-mode games 😀

Thanks!

georgel wrote on 2020-02-07, 12:27:

[..] back then CGA was used mainly with RGB monitors, not with NTSC color TV sets that hardly could display 80 columns text.

Interesting. That's why I love vogons forums. You always learn something new.
I was under the impression that CGA color-wise was such an eye cancer that people back then reverted to monochrome monitors (on CGA) on their own will
and that this was the reason that most clones with built-in CGA labeled their RCA/Cinch connectors "MONO". 😁

Edit: I was just kidding, of course. However, CGA on mono display looks fine. Especially on green/amber screens of the time.
An analog B/W TV set isn't bad either, for this purpose. The blurry RF/Composite connection and the mask-less TV screen have a certain charme.
Almost like analog anti-aliasing. The overall picture is nicer, softer than that of digital RGB I think.

Edit: I also forgot to mention. CGA was *very* popular on laptops and portables of the day.:
Early, low-priced (by comparison) monochrome Liquid Crystal Displays (LCDs) were capable of 640x200 pels (that's hi-res CGA!).
That CGA output normally was without aspect correction, of course, because this would have required 640x400 or non-square pixels.
Anyway, these screen could do 80 chars@25lines. Gratefully, no (?) vendor ever sold such machines with 320x200 screens (CGA standard resolution).

Edit: Small fixes. Also: Olivetti M24 and some Toshiba laptops did enhance (or rather, did "fix") CGA and added 640x400 mono mode. 😀
See Re: Olivetti/Logabax/AT&T/Toshiba 640x400 hi-res graphics mode Edit: Re: ColorGraphicsAdapter (CGA) Thread (Games/Demos/Intros/Slides)