DonutKing wrote:

With the SIPPs you can actually solder pins on SIMMs and use those... If you have the patience for it.

Yeah I did read that somewhere but no, I don't have the patience! Thanks for the tip though.

I've decided that 1MB is enough for this bad boy anyway. Anything that needs more will get a taste of my 386**

** I have too many computers.

DonutKing wrote:

With the SIPPs you can actually solder pins on SIMMs and use those... If you have the patience for it.

Wouldn't it be easier to solder on some SIMM slots?

sliderider wrote:

DonutKing wrote:

With the SIPPs you can actually solder pins on SIMMs and use those... If you have the patience for it.

Wouldn't it be easier to solder on some SIMM slots?

I don't think you even need to solder them, if you had some SIMM slots you could just push the pins into the SIPP holes.

DonutKing wrote:

For the PC Speaker, I just spliced a resistor into one of the speaker cables. I think I used a 16 ohm resistor, and that quietened it down a bit.

This might be a stupid question, my electronics knowledge is not too flash. But instead of a standard resister, could I use a trimpot instead? I'd like to be able to adjust the PC speaker volume, so if for example I put something like this...

http://www.jaycar.com.au/productView.asp?ID=R … or&form=KEYWORD

... into one of the speaker wires, would it work? My simple understanding is that this is a variable resister which would allow me adjust the resistance to the correct level, thereby allowing me to adjust how hard the speaker is being driven.

Thanks for any help.

For voice levels, you need a logarithmic trimmer/trimpot (variable resistor), because our ears hear logarithmically.
For us to hear a sound at double level, the sound itself needs to be 10 times stronger.

Keep in mind that trimmers are not made for this job, they should burn themselves if the speaker consumes more than 0.1 watts, and I'm not sure if 1-2-5W trimmers exist...
But you could try it. 😀

A couple of sound upgrades for the 286. Firstly the PC speaker, which was ear splittingly loud. The answer to that problem was obvious – ear plugs! But not for me – those cheap foam ones from the chemist were the perfect size to plug into each of the 5 holes inside the case which were allowing the racket out, and now it’s far more bearable.

And secondly this nice ’87 Adlib, courtesy of DonutKing. I always wondered as a kid what the Adlib option was in game’s sound menus, but that was probably ’92 or so, by which time the Sound Blaster had blasted them out of the market. It’s perfect for this humble little machine, and just the thing for playing Keen, Prince of Persia, etc.

Another sound upgrade for this machine, this time to a Sound Blaster 1.5 (CT-1320C). It’s a handsome card and getting relatively collectable, but I bought it for the sole purpose of experiencing CMS firsthand. I do have a Sound Blaster 2.0 but it’s the wrong revision for easily upgrading to CMS, so when the 1.5 came along for a reasonable price I snagged it.

The first couple of Philips SAA1099P chips I had turned out to be duds – one produced nothing but a nasty crackle (even when not in use) and the other was clearly second hand and so fragile the legs were literally falling off. Another visit to our Chinese friends via eBay secured me 4 new ones, which turned out to be clones when they finally showed up (branded ‘NXP’), but they were actually new this time and seem to work fine.

I really like the CMS sound, it reminds me of the Commodore 64’s SID. Very melodic and very “computer game”. Silpheed for example is greatly enhanced by its CMS tunes, and now my little 286 supports 3 sound standards – wow! 4 if you include PC speaker 😀

Very nice! I love 80286s: my first own PC was a Philips 80286. FYI: NXP is Philips SemiConductiors. They spun off from Philips in the mid 2000s.

Nice 286. The case is great.

What games do you play on it?

BuuBox wrote:

Nice 286. The case is great.

What games do you play on it?

I haven't played games much yet to be honest, I've probably spent more time messing around with the old DOS word processors that it had on the HDD when I got it - I have a thing for word processors 😜

I'll break out some early King's Quest on it one day.

Haven't seen this one before... Great setup! Clean and neat as usual. Considering sound, there's also a Covox solution, period-correct and craftable.

btw, I got the exact same hard drive extracted from 286-12 machine. Redhill hardware guy wrote about it: http://www.redhill.net.au/d/16.php
It is very interesting construction-wise, it has only one disk and is small yet full-height with these strange mounting brackets under the drive. When it comes to speed, I guess it is as good as a period-correct 286 could get.

I finally got around to benchmarking this machine as per the request of a member here. The following benchmarks were run:

- 3dbench (version 1.0 not 1.0c)
- Norton Sysinfo 8 - CPU
- Checkit 3 - CPU, Video, HDD
- NSSI - CPU
- Pmips

And the following results were achieved:

3dbench:
6.4

CheckIt

Main System Benchmark:
CPU Turbo ON (16MHz): 11.20 times IBM PC-XT
CPU Turbo OFF (~8MHz): 5.64 times IBM PC-XT
Math Turbo ON: 11.35 times IBM PC-XT
Math Turbo OFF: 5.59 times IBM PC-XT

Video:
BIOS Video CPS: 9.19 times IBM PC-XT
Direct Video CPS: 9.87 times IBM PC-XT

HDD:
Transfer speed: 5.20 times IBM PC-XT

Norton SI:
Computing Index (CI), relative to IBM/XT: 17.6
Disk Index (DI), relative to IBM/XT: 5.2
Performance Index (PI), relative to IBM/XT: 13.4

PMIPS

General Mix: 1.7
Integer: 1.9
Data Transfer: 3.6
String: 1.8
Control Transfer: 1.6
Flag Control: 4.6
Logical: 2.0
Jump: 2.7
Weighted Average: 2.6

NSSI:

CPU Performance: ~3960 Dhrystones (this result jumps around)
FPU Performance: 554 KWetstones

Not bad results for a 286 from what I can tell (some of the bencharks compare the results to 386, etc). I'm currently using a Tseng ET4000AX VGA card in this machine but I'm thinking of swapping that out for a card with better CGA compatibility, just for fun. In saying that, I probably won't. This machine hasn't seen the light of day since I finished restoring it - I just never seem to find an excuse to use it.

Anyway, I hope these results are of interest.

286? VGA? Adlib? Sounds like a great system for 1991 donut 😀

Thanks for the benchmark results 😉

Scali wrote:

286? VGA? Adlib? Sounds like a great system for 1991 donut 😀

Amazing stuff! Well done.

kixs wrote:

Thanks for the benchmark results 😉

My pleasure! I've had a good play with it now that it's out of storage. I'm in the process of improving its CGA compatibility with help from this excellent thread. Good times 😎

Nice 286 ! Mine is up and running as well, previous issues were discussed here.

Take a look at the Mem card in my Packard Bell.. could use it to boost yourself to 2MB RAM or higher if you wanted.

Packard Bell Legend VI (Issues now)

Great job and attention to detail. Well done. Looks fantastic!

Great 286 Machine, i wish i had one like this too 😀
The Adlib Card is something i never had.
I had a Sound Galaxy SGBXII in my 386SX long time Ago.

Thanks for the kind comments.

One thing that's bothering me is that it's floppy only for getting files onto this machine. I've considered the Gotek but I don't like the aesthetics of them; I have a spare IDE->CF adapter lying around so I might try that out as slave HDD. Hopefully the BIOS is up to the challenge.

I've been having a ball messing around with a couple of different ISA VGA cards. I've settled on a Trident 8900C, which outputs a very handsome VGA image and emulates CGA very nicely too - including CGA's 60Hz refresh rate.

One thing that I found interesting was that Double Dragon runs way too fast in VGA mode - even with turbo off - but when I put the Trident into CGA mode and run the game, it plays at the correct speed. Why would this be? Were some older games coded to rely on refresh rate?