• Please review our updated Terms and Rules here

AST XFormer/286 BIOS Checksum error

The BIOS chip for the ODD is dated 1987 Version 1.2 JL27C128D/029031, made in Singapore in 2009 while the EVEN is L27C128D/047010, made in Japan 2013. Of course, I was trying to match the 27C128 since the JL and L series didn't seem to exist. If the power required for the D27128 is 21 Volts the power adapter for the GQ-4x4 is way under powered at 9-10 Volts. According to MCUMall's website (URL: https://www.mcumall.com/store/index.php?route=product/product&path=69&product_id=205), the URL shows this power supply for the GQ.

Chuck(G) thank you for the suggestion. The Landmark Supersoft diagnostic for ODD and EVEN are 16-KB each. So assuming the 256 is programmable from the GQ-4x4, the offset address is 0x000000 where would the second entry address reside since the 256 would be programed twice?

sqpat: I did see AM27128A-2DC on eBay and I have ordered those since the Intel requires high voltage.

Malc: Where did you get your Data I/O programmers guide for old chips?
 
alejack12001 said:
To get a match of this chip from the GQ is not easy. I have been using all under Type, AMD as manufacturer, Device was limited to AM27128A and AM27C128. I may have missed the 27128 showing 21V.
Click to expand...
Ideally, you purchase chips that your EPROM programmer supports.

On my GQ-4X, 'generic' options are also available. I am guessing that on the subject of 'generic', the GQ-4X maker would say something like, "If the make-model of your device is not available for selection, then try the 'generic' option, noting that there is risk, because your device may get programmed using parameters that are not within the maker's stated/recommended parameters."

I have a 27128 (no A suffix, and not 27C128), and on my GQ-4X, I can successfully program it via the 'generic' option of TYPE=ALL, MANUFACTURE=ALL(GENERIC), DEVICE=27128(21 VPP), but only if I use an AC adapter.

Does your GQ-4x4 also have the TYPE=ALL, MANUFACTURE=ALL(GENERIC), DEVICE=27128(21 VPP) selection ?
If so, and you can get yourself a suitable AC adapter for your GQ-4x4 , then you should be able to program your AM27128 via the generic option.
Perhaps there is a suitable AC adapter about the house that you can borrow.

alejack12001 said:
If the power required for the D27128 is 21 Volts the power adapter for the GQ-4x4 is way under powered at 9-10 Volts.
Click to expand...
It does not work that way, because the EPROM programmer can boost the supply voltage internally. For example, my GQ-4X can program Vpp=12.5V chips (e.g. AM27128A) with only a +5V supply (+5V via the USB connection).
The requirement for an AC adapter is about the power requirements of the chip being programmed.
 
alejack12001 said:
Malc: Where did you get your Data I/O programmers guide for old chips?
Click to expand...
I don't have a guide, What i meant was my programmer can detect a faulty eprom and spit's out a meaningful error, Unlike the more recent programmers which can leave one pulling one's hair out because the old eprom they are trying to program is faulty or not even supported.
 
I also own the older model GQ-4x not the newer GQ-4x4, I bought it new back in 2010 to program newer chips my older programmers can't, I have successfully programmed a few old ( Tested Good ) Eprom's that require a VPP of 21v using the GQ-4x but like Modem7 said you must have an AC adapter connected otherwise it won't work.
 
Once the chips ordered along with the GQ-4x4 power supply arrives and if I am able to install the Landmark Supersoft EPROM based startup software and it detects some sort of fault that is not repairable, then would a 5170 motherboard fit into a 5160 case? I am trying to plan ahead for the worst case scenario.
 
alejack12001 said:
Once the chips ordered along with the GQ-4x4 power supply arrives and if I am able to install the Landmark Supersoft EPROM based startup software and it detects some sort of fault that is not repairable, then would a 5170 motherboard fit into a 5160 case? I am trying to plan ahead for the worst case scenario.
Click to expand...
No, but I believe the board from a 5162 (XT-286) would fit.
 
5162 boards will fit but are super expensive. I gave up years ago trying to get one. Could always do what I did, get a super early 386sx board and throw it in. Get a little extra memory and 16 bit slots.
 
Yes, I started looking at 386 motherboard thinking it would be a sufficient substitute should this AST motherboard be unrepeatable. Chuck(G), your right the 286 IBM motherboards are insanely expensive. I guess it's supply and demand that governs the price.
 
The Landmark Supersoft tests can work with CGA/MDA cards. I have an MDA card that came with the machine and I have an old tube monitor that has a MDA/CGA connection. What I don't have is a MDA/CGA cable. So, stupid question: would a 9-pin serial cable work as a subsitute for the MDA/CGA cable just for this test?
 
Thank you Chuck(G), I wanted to see if it was possible to use a serial cable. I had some success last fall with a set of parallel cables with a two-position switch to share an AT&T 319 monitor between two 6300's. The switch and cables work between the two machines when I have them both up and running. I will be getting a CGA/MDA cable as I wasn't sure if my serial cables were straight through.

So, I wanted to ask about the beeps associated with the Landmark Supersoft software. The objective is to determine what is wrong with this AST XFormer/286. So, should I connect my external battery source so that the software doesn't beep over that issue? I plan to record the beeping and photograph any picture that might come up on the display. Then try to determine what is the problem. I'll be be back on my findings.

I finally got the power adapter for the GQ-4x4 EPROM read/writer. However, the only EPROM that would write the Landmark Supersoft software was AM27128A. The other two EPROM's, namely AM27128A-4DC and the Intel D27128 required Vpp voltages (21-22 Volts) that the read/writer couldn't give even with the power adapter. The power adapter is only 9 volts and 1 Amp. I am posting this to give your users some idea what I experienced to program EPROM's for 80286 machine.

Check(G): I read that you were ill, but recovering. Take care, good to hear from you again.
 
Any beeps are documented in the manual that goes with this--I think that there's a copy on MZD.
I've completed therapy and am still feeling okay, although somewhat tired. We'll get the initial assessment next month as to whether or not it did any good. Fingers crossed.
 
alejack12001 said:
I finally got the power adapter for the GQ-4x4 EPROM read/writer. However, the only EPROM that would write the Landmark Supersoft software was AM27128A. The other two EPROM's, namely AM27128A-4DC and the Intel D27128 required Vpp voltages (21-22 Volts) that the read/writer couldn't give even with the power adapter. The power adapter is only 9 volts and 1 Amp. I am posting this to give your users some idea what I experienced to program EPROM's for 80286 machine.
Click to expand...
The AM27128A-4DC requires 12.5v VPP not 21v, The Intel D27128 does require 21v VPP, It's possible that:
1. Both Eproms are bad.
2. Your new power adapter is not working as it should. ( for the Eproms that require 21v VPP )
 
Chuck(G) said:
Any beeps are documented in the manual that goes with this--I think that there's a copy on MZD.
I've completed therapy and am still feeling okay, although somewhat tired. We'll get the initial assessment next month as to whether or not it did any good. Fingers crossed.
Click to expand...
MZD, I am a loss as to the acronym. Can you give me more.

Good luck on your test results.
 
You must log in or register to reply here.
Back
Top