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XT "Accelerator" Boards

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nymetropolitans

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I was reading earlier about the several different models of XT accelerator boards (ie: Orchid Tiny Turbo, 286 Express, etc.) and it got me wondering why it appears these were exclusively for 8088 based systems and not 8086? I could have it wrong, you'll have to pardon my ignorance as I never had much experience with the original era of PCs....just a little bit before my time!

They seem to have been a pretty popular upgrade in their day, I didn't know that CPU upgrades like that had existed before the 486 era! You learn something new every day :cool:
 
Market share?

I am quite sure that the number of 8088 systems far outnumbered the number of 8086 systems out there. The 8086 systems were a tiny sliver of the market.
 
Some of these boards plugged into the original ISA bus, which is 8-bit. They also had their own local memory.

I suspect that if your 8086 system is able to interface to standard ISA cards, you might have some success using one of these accelerators.
 
All of the ISA upgrade boards I have seen also use a ribbon cable that plugs into the CPU socket, so unless you can find one that doesn't use this method you are out of luck. Also, most of those boards were for 4.77MHz systems, so trying to use one on an 8MHz XT will probably not work well.
 
A smidge OT:

Does anyone have one of the 8086 PC Clones, such as the Stearns PC kicking around? If so, how's the ISA support?

I recall that ETA Systems bought the Stearns boxes by the truckload, as Stearns was a Minnesota outfit. Wonder if any of them have survived?
 
I know about the Amstrads and seem to remember that the NEC APC and the Eagle 1600 also used 8086 CPUs (as well as the Grid laptops).

The Stearns used an 8MHz 8086 and had 4 proprietary expansion slots and one ISA PC-compatible one.

There were some oddball aspects of the Stearns, IIRC. The display was 26x80, for example and allowed for 256 user-definable characters in addition to the normal ROM-resident ones. They also had their own flavor of MS-DOS that provided emulated ROM BIOS support for PC applications.

One of those "almost PC" PCs that one never sees in collections nowadays.
 
nymetropolitans said:
I was reading earlier about the several different models of XT accelerator boards (ie: Orchid Tiny Turbo, 286 Express, etc.) and it got me wondering why it appears these were exclusively for 8088 based systems and not 8086?
Click to expand...

Because most 8086 systems were 7.16MHz or faster (I have never seen a 4.77MHz 8086 PC) and at that speed and bus bandwidth (the 8086 can grab two bytes in 4 cycles; the 8088, only one byte), it was already enough of an improvement over a 4.77MHz 8088.
 
Trixter said:
Because most 8086 systems were 7.16MHz or faster (I have never seen a 4.77MHz 8086 PC) and at that speed and bus bandwidth (the 8086 can grab two bytes in 4 cycles; the 8088, only one byte), it was already enough of an improvement over a 4.77MHz 8088.
Click to expand...

...but there were 286 and 386 accelerator cards for 5150/5160 type PCs, too!

Were there any 80186 accelerator kits for 8088-based systems?
 
Chuck(G) said:
...but there were 286 and 386 accelerator cards for 5150/5160 type PCs, too!

Were there any 80186 accelerator kits for 8088-based systems?
Click to expand...

I have one of those accelerator cards.........an Orchid PCTurbo 186

Picked this up awhile back but haven't had time to test it yet :)

This particular one does not use a cable to plug into the 8088 socket.
You leave the 8088 in place.
 
I decided to pull a PC Tech Journal product guide for 1987 off the shelf and take a peek and a refresher.

Anyone have a Microsoft Mach 20? 8MHz 286 ISA plugin (with a special bus-mouse socket) with optional daughterboards for 3.5MB memory and floppy controller (supports 1.44 and 1.2MB media)? Guaranteed to run MS-OS/2.

How about the AST FlashPak? 8MHz V30 ISA plugin.

How about a Cortec 64180 card with 512K of memory onboard? Run them CP/M apps!

Or the Definicon DSI-785 68020 ISA card? Or the DSI-32E NS32032 card?

Or the Diamond Trackstar with 6502 and Z80 CPUs?

And an almost endless list of 286 and 386 accelerator cards with everything from built-in EGA to SASI onboard.

One forgets how amazingly diverse offerings were back then. Of course, if you had a 5160 and were lusting after an 80286 upgrade, you could always visit Uncle Woo's House of Kung Pao Chicken and CPUs and just buy a "Baby AT" mobo to drop in, probably for less of an outlay than an Aboveboard 286.
 
mikey99 said:
I have one of those accelerator cards.........an Orchid PCTurbo 186

Picked this up awhile back but haven't had time to test it yet :)

This particular one does not use a cable to plug into the 8088 socket.
You leave the 8088 in place.
Click to expand...

Have you had a chance to test this yet? How did it work and what kind of speedup did you see? (I'm curious to know how well an acceleration board that doesn't replace the CPU can work). What speed does the 80186 run at?
 
Trixter, thanks for reminding me :) It's cold in my garage today but I'm
curious about this card now. I did try this just now and when I boot the PC with the
Orchid card I get a 4098 201 error. The diskette starts to boot and then hangs.
The Orchid has 256K and I left the MB switch settings the same
because I pulled an IBM 256K memory card to plug in the Orchid.
There are some switches on the Orchid card, I'm just guessing
they are set correctly. I pulled the Orchid , put the IBM Memory
card back in and the PC boots normally. Unfortunately I have no docs
on the Orchid card :-( If I can get this to work I'll run some benchmarks
like speed600 to see what effect this card has and see if the benchmark
can recognize any speed increases.

Did some searches on Google, found some references to this being 8MHZ

Also a reference to a test report :

PC Tech Journal Jun 85: Orchid's PCTurbo-186


Trixter said:
Have you had a chance to test this yet? How did it work and what kind of speedup did you see? (I'm curious to know how well an acceleration board that doesn't replace the CPU can work). What speed does the 80186 run at?
Click to expand...
 
Last edited:
BTW< here's one just like the card I have :
http://cgi.ebay.com/Orchid-PC-Turbo-186-coprocessor-card_W0QQitemZ230328298355QQcmdZViewItemQQimsxZ20090301?IMSfp=TL090301123007r8779

Heres a brief review I found on the web , sounds interesting,
but I dont have the required software.......
Subject: PC Orchid- 186

I've used one of these boards for a couple of years now. It was more or
less discontinued when Orchid came out with their 286 Turbo Board.

The daughter card probably is memory although Orchid offered a smaller
daughter card which contained a serial port and video enhancements. The
memory card can bring the total memory for the 80186 processor to 704K.

The card is OK. Bench marks indicate that processor speed is, overall,
about 2.5 times that of a regular PC (the 80186 running at 8MHz, a
slower version was also offered). Harddisk access is a little slower.

This card allows one to have almost the equivalent of 2 PC's in one box
since the 80186 has its own dedicated memory. I can switch between the
TURBO card and the regular PC's 8088 from the command line. If I am in
a program I can shell to DOS for the switch and return later where I
left off. The price for this is performance of the I/O devices such as
disks and monitors.

To get this card to run you will need a disk of support programs from
ORCHID if one wasn't available.
 
Last edited:
Ok, after reading more, it appears the memory on the Orchid
card is dedicated to the 186 processor. So I put my IBM Memory
card back in and the Orchid card and the PC will now boot.

Just need to figure out if the 186 is actually doing anything now :)
(as I rifle through 100 boxes of diskettes looking for speed600.exe)

Update: Ran speed600, and it gives no indication of any speedup.
Pressing the switch on the back of the card does nothing. Will
need to do some more research about exactly how this thing works.
I would think that somehow the card is enabled by the switch or software
driver so running a program is actually running on the 80186.
 
Last edited:
mikey99 said:
Just need to figure out if the 186 is actually doing anything now :)
(as I rifle through 100 boxes of diskettes looking for speed600.exe)

Update: Ran speed600, and it gives no indication of any speedup.
Pressing the switch on the back of the card does nothing. Will
need to do some more research about exactly how this thing works.
I would think that somehow the card is enabled by the switch or software
driver so running a program is actually running on the 80186.
Click to expand...

I think you'll find that it's a software driver that's needed. I seem to recall that this type of accelerator card used the 8088 for I/O, but took over when computation was involved.
 
Chuck(G) said:
I think you'll find that it's a software driver that's needed. I seem to recall that this type of accelerator card used the 8088 for I/O, but took over when computation was involved.
Click to expand...

I did some searches on Google, havent found the drivers.
It would help if we knew the actual name of the file.

Anyone have the PC Tech Journal ?

Jun 85: with the article Orchid's PCTurbo-186
 
Chuck(G) said:
Were there any 80186 accelerator kits for 8088-based systems?
Click to expand...

I can't answer that, but I do remember buying a thrift store computer that had an ISA board with an 80186 chip on it and a toggle switch that was mounted on the back plate of the card. Who knows?

A bit O/T, but does anyone know of software that was written for the 8086?

Thanks,
Sean
 
Floppies_only said:
A bit O/T, but does anyone know of software that was written for the 8086?
Click to expand...

That should be pretty easy--any software that required 16-bit I/O transfers for operation. That would include drivers for 16-bit I/O devices as well as certain 8086 BIOS code.

Otherwise, it would be pretty hard to find something that was restricted to an 8086, as the instruction sets don't differ and the memory read/write operates pretty much the same.
 
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