• Please review our updated Terms and Rules here

Maynard Electronics SURPRISE! V20 Accelerator Board

mmruzek

mmruzek

Experienced Member
Joined
Sep 28, 2011
Messages
227
Location
Michigan, USA
I recently purchased an IBM PC 5150 with an unusual CPU Accelerator option. It is the Maynard Electronics SURPRISE! board. This device comes with a 40 pin CPU socket adapter that converts the 8088 CPU location into a small edge card socket. (See photos). The card socket accepts a small PCB board with a NEC V20 CPU and support logic.

sur1.jpgsur2.jpgsur3.jpgsur4.jpg

The manual states "The SURPRISE! card is an inexpensive accelerator card for the IBM PC. This card increases the speed at which you computer runs by up to two and one half times." "SURPRISE! is also unique in that it is made up of hardware and software. The hardware increases the speed at which the computer runs programs. The software makes DOS and screen functions happen faster."

I am in the process of experimenting with this device. I am wondering if anyone else on VCF is already using one? Also, this looks like a setup that would be fairly easy to clone. The only challenge I see there are the 2 PAL devices, which I don't have experience reading and writing... my understanding is that these can be copy protected with a fuse? Would that be a show stopper? Thanks!

Michael
 
Most production PALs have the security fuses blown, in my experience. PALs can be reverse-engineered by a number of techniques. Combinatorial ones are much easier to crack than registered ones. The most straightforward way is to work up a schematic and figure out what they do.

This board and others like it were pretty much obsoleted by the import "turbo" clones.
 
You're welcome.

This was mostly done because I'd picked up an AT&T 6300 with a missing PAL on the video card--and then I remembered that I had a couple of Trantor T130B SCSI adapters that were also missing the PAL. So it was mostly a matter of enlightened self-interest.
 
NEC V20 CPU should work in the 8088 socket as drop-in replacement (at 4.77Mhz). This card seems a clock-doubler for the CPU.

Could you run CPU speed test utility like NU SYSINFO or Microsoft MSD ?
 
You think it's just a standard IBM PC?

*opens up case*

SURPRISE!

lol :D

I love the names of products back then. These days they try and find some cool name, say a greek God or some mythical creature for example, but back then a simple phrase would suffice. Surprise! Love it.

Neat looking product and would be interested to see what it would bench at.
 
Flamin Joe said:
Neat looking product and would be interested to see what it would bench at.
Click to expand...

I suspect not as well as a "native" 9.5 MHz cheap Taiwanese clone "turbo" PC. You have to understand that it uses the standard-speed PC memory; i.e., no local memory on the card. So better than 4.77MHz 8088, but not as good as it could be.

But let's see the numbers... :)
 
I suppose you can piggyback the 8087 on the V20 (with a few small diversions). I think the question has been asked before.

But no, you wouldn't want to use the motherboard 8087 socket--that's not where your code is being executed.
 
alecv said:
NEC V20 CPU should work in the 8088 socket as drop-in replacement (at 4.77Mhz). This card seems a clock-doubler for the CPU.

Could you run CPU speed test utility like NU SYSINFO or Microsoft MSD ?
Click to expand...

Thank you for the link to Chuck's PAL post... That information answers many of my questions regards cloning the PAL.

I will be scanning the paperwork that's included with this device in the next few days. There is a section describing compatibility with the 8087 co-processor. The answer is rather involved and depends on what applications you are running.

Also, regards the CPU speed test, I ran Norton SI V. 4.5 with the following results: Computing Index of a stock PC with an 8088 = 1.0, Computing Index of a PC with the SURPRISE! running in slow mode = 1.8, Computing Index of a PC with the SURPRISE! running in fast mode = 2.8 (A screenshot of this test is attached.)

bench.jpg
 
Hi, As promised here is a link to the scans of the manuals for the SURPRISE V20 Accelerator board.

http://www.mtmscientific.com/surprise.zip

As it turns out the 2 PALS on this device were not locked, and I was able to read the JEDEC files OK using a SUPERPRO II. I am in the process of laying out the PCB artwork to clone this board. This device can be hardware jumpered to start in fast mode, or with the provided software it can be toggled fast or slow using the keyboard. The software also includes a SYS file that is described as being able to 'speed up' some of the more common DOS routines. I am including a link to the software on the off chance that some of you code sleuths have an interest in investigating how it works. I used a HEX editor to look at it... but that's about all. Would appreciate any insights. Thanks! Michael

http://www.mtmscientific.com/sur_soft.zip
 
How is the reverse engineering of the surprise going? 16mhz nec v20 CPUs are available, so could the design be tweaked to be clock tripled?
 
rorypoole said:
How is the reverse engineering of the surprise going? 16mhz nec v20 CPUs are available, so could the design be tweaked to be clock tripled?
Click to expand...

Hi, Thank you for asking about the cloning of the Surprise! accelerator card for the 5150 PC. This has turned out to be a lot more work that I expected. At first I thought it would be possible to follow the top and bottom traces by eye, but I have had to use a continuity meter for many of the traces. It also looks like a couple of the traces were cut, and several more traces were added using wire and hand soldering. The good news is that I have the first draft of a circuit schematic... the bad news is the accelerator card has stopped working! (BTW: Does anyone else have one of these?) Here is a link to what I have so far:

http://www.mtmscientific.com/surprise_6.jpg

I would appreciate comments and insights that forum members might have about how this card works. I will post more information about this project after I do a second pass on the point-to-point on the PCB. Regards, Michael
 
Hi,

For some time, I participated in a discussion about cloning the board?

That was in 2017. Has there been any progress? Did you finish the PCB?

I have an IBM 5150 and I keep it in a small museum of retrocomputers with philanthropic income for abandoned animals. I would love a solution that will make it faster for games.
 
You must log in or register to reply here.
Back
Top