New D8B user. A few more issues

[scottosterloh]

Wow that is a lot of information. I can't thank you enough for your knowledge and the time it took to share it. You are awesome my friend.

[scottosterloh]

I pulled the small memory and tried to start V5.1 with both a single 256Mb and 2x128mb and in both cases the monitor won't even wake up. Still not sure what's happening.

[Y-my-R]

Thanks for the flowers Looks like it didn't help, though...

What you're describing sounds like the new memory isn't getting recognized. I don't think the mainboard can deal with a single 256MB stick, but not sure.

The "old" mainboard was made by Amptron. Model name is PM-9800. If you search for the manual, it will give you specifics of what memory is supported. (Not sure if the mainboard manual is in the database here on this page... I downloaded that manual a long time ago from 'somewhere'... don't remember where).

I just looked, and this is what it says for memory:
•Up to 256MB of main memory in 4 (2 banks) auto banking 72-pin SIMM slots for Fast
Page Mode or EDO DRAM, and 2 168-pin DIMM sockets for SDRAM, Fast Page Mode
DRAM, or EDO DRAM modules.
•Supports 64M-bit (16M X 4, 8M X 8, 4M X 16) technology DRAM/SDRAM

When I upgraded mine, I bought the following memory, and it works for me (it was really cheap, too, but the page now says they have zero available):

https://tinyurl.com/ycl6jd75

If you search for the same type of memory, you might still find it for a similar low price somewhere, though.

When it comes to computer memory, there aren't really any "settings" to get it recognized. Either the mainboard accepts it, and it boots far enough to start counting up the memory shortly after powering on... or the screen stays dark. And if you have one of those little computer-beep speakers installed, it would repeatedly make beep-beep-beep sounds to indicate that the memory isn't recognized. But the d8b computer doesn't have one of those speakers installed from the factory, so you won't hear anything, and the computer just won't do anything after powering on, other than that the fans are spinning). For troubleshooting, I have a tiny such speaker, that just connects to the pins on the board, so I can hear the error-beeps, and look up what the beep-sequences mean. But your situation definitely is that the memory isn't recognized.

In short, the behavior of the computer is that either the memory is recognized and counts up shortly after powering on, or it isn't recognized and the screen stays dark. The memory you installed clearly isn't recognized.

If you installed memory you had "lying around", then it's likely too fast for an old computer like the d8b uses, and the memory you installed can't operate at the slow bus speed the d8b runs on (I think it's 100 MHz on the bus).

That's why you need memory that is either old enough to run at such slow speeds, or manufactured for use in such an ancient computer (like the link I shared).

One word of caution for the memory purchase link I shared, though... I had ordered two sticks, and expected them to be identical, but they weren't. It ended up working for me, but if you order two sticks together, you'd think you'd get a matched pair, etc. So, this means that you might get slightly different memory sticks every time you order from there, and this could of course have an impact on if they end up working in the d8b or if one might cause trouble. However, if the specs are right (and that should always be the case when the specs are shown in the item description (i.e. 100 MHz SDRam 168 pin DIMM)), then you have a high chance of these working with computers that expect memory with these specs. But anyway... they have 0 available from the link I shared anyway, so you'll have to search for this elsewhere.

Alright... I hope you can find memory the d8b computer likes! Sorry to see it gives you so much trouble to get it working. But again, best of luck!

[Y-my-R]

Oh, and I just found a section in the mainboard manual, that is a bit more clear about the memory requirements. So, the maximum it can handle per memory stick in the DIMM slots (the 2 longer ones) is 128 MB. That confirms that the 256MB stick you have won't work. It also mentions, that you can't use SIMM modules (the smaller memory sticks) and DIMM modules (the longer memory sticks) at the same time.

It doesn't talk about the bus speed in the manual (i.e. the 100 MHz... the 70ns speed is how quickly the memory responds when accessed... that's a different thing. I'd assume it doesn't mention the slow-speed requirement, because at the time the manual was written, 100 MHz was still a common memory speed, and there was no need to clarify that it shouldn't be much faster). Anyway, here's what the manual says:

Bank 0:
SIMM1 & SIMM2 2 X 4MB / 8MB / 16MB / 32MB / 64MB
(72 PIN SIMM)

OR

DIMM2 4MB / 8MB / 16MB / 32MB / 64MB / 128MB
(168 PIN DIMM)

Bank 1:
DIMM1 4MB / 8MB / 16MB / 32MB / 64MB / 128MB
(168 PIN DIMM)

Bank 2:
SIMM3 & SIMM4 2 X 4MB / 8MB / 16MB / 32MB / 64MB
(72 PIN SIMM)

MEMORY CONSIDERATIONS
•The mainboard lets you add up to 256MB of system memory through 4 SIMM and 2 DIMM
sockets on the board
•Each bank consists of two 72-pin SIMM modules, or a 168-pin DIMM module.
•You cannot install memory into SIMM1 & SIMM2 and DIMM2 sockets at the same time
•The speed of all SIMMs and DIMM modules have to be faster than 70ns
•Uses Fast Page Mode or Externded DATA Out (EDO) for the SIMM sockets
•Uses Fast Page Mode, Extended DATA Out (EDO) or Synchronous DRAM (SDRAM) for
the DIMM sockets.
•The function of Bank 2 will not be available for use when using 64M-bit type of SDRAM in
any DIMM slot.