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merlinkv
Spain
6 Posts |
 Posted - 11/16/2011 : 09:46:11
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Hi,
As title saids I cannot program AMD 27C400 & 27C800 EPROMs.
Programmer: GQ-4X
Adapter: AD-54
EPROM's: AMD 27C400 & 27C800.
UV Eraser: YES
DC Power: From powered USB port / DC Power supply 9v DC 1000mA (correct polarity).
All chips UV erased and Blank check OK
As I'm an Commodore Amiga collector, I want to make backups of my legally owned ROMs... 1.3, 2.04, 2.05, 3.1, 3.9 and also to program updated versions of this ROMs for my personal use.
But no wayt to write the .rom/.bin files I correctly extracted from my Amiga's. All times the programmer stops writing the fisrt bytes.
I have the same troubles described in this Topic http://www.mcumall.com/forum/topic.asp?TOPIC_ID=4331
One strange thing.. I can write/verify a full buffer of "FF" or "00" with 100% success.
Any idea?
Thanks in advance |
Edited by - merlinkv on 11/16/2011 09:50:39
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| Reply #1
kire_online
Australia
9 Posts |
Posted - 11/16/2011 : 13:17:53
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| Just wondering if it's the .bin vs .rom file difference ? |
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| Reply #2
ZLM
2937 Posts |
Posted - 11/19/2011 : 21:27:41
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Those two files are no different.
Try on V3 and V4 jumper to see if anything different.
See this video, the video shows how to avoid pin contact issue.
www.youtube.com/watch?v=Y9-aRPKyL-s
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| Reply #3
merlinkv
Spain
6 Posts |
Posted - 11/20/2011 : 00:56:07
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Hi again,
V3 & V4 jumper has no difference.
EPROMs fits firmly in the socket not like showed in the video.
It seems like a problem in the code interpreter of the software. Why?
Test 1: Original ROM
- If I insert one original Amiga ROM in the socket, the programmer can read the ROM
- Of course, the readed code is not usable later on Amiga because some bytes are readed in wrong format.
- With this "bad" code in the buffer, 524.288 bytes in size, I can write a full 27C400 EPROM at any speed with 100% success.
Test 2: ROM image well extracted from my Amiga.
- Loaded Kickstart 3.1 in the buffer, size 524.288 bytes
- Blank Check: OK
- Writing at any speed stops at the first bytes, not the same address each time.
Test 3: Buffer filled by "00"
- The programmer can write a buffer "00" filled at any speed with 100% success.
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The code in all tests are different, but size of the buffer are the same 524.288 bytes.
As I said, it seems like an issue in the code interpreter of the software. |
Edited by - merlinkv on 11/20/2011 01:07:04 |
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| Reply #4
ZLM
2937 Posts |
Posted - 11/20/2011 : 18:07:18
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"because some bytes are readed in wrong format" ____ Can you give me an example?
Can you try to write the chip without the power adapter?
Have you ever write any chip successfuly with this adapter? |
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| Reply #5
merlinkv
Spain
6 Posts |
Posted - 11/21/2011 : 07:05:25
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Hi again,
Yes, of course, I can share examples:
ROM I want to clone: Original Amiga ROM Kickstart 3.1 40.63
1.- From original ROM chip
Code readed:
Image Insert:
182.23 KB
In this case I can write the code to EPROM 27C400 with 100% success.
Also if I save the readed buffer, in bin or hex format, and reload in the buffer I can write the EPROM without any problem
2.- From ROM image (.rom file)
Code readed:
Image Insert:
180.99 KB
In this case the programmer stops writing at the first bytes, and not at the same address each time. |
Edited by - merlinkv on 11/21/2011 10:24:59 |
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| Reply #6
ZLM
2937 Posts |
Posted - 11/21/2011 : 10:54:23
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I think you must used a different chips on those images when you writting.
I did not see either hardware or software went wrong.
I only can guess your second chip used on the second write is not a good chip.
Try to use the first chip to program again with your second data. That will confirm if it is the chip problem.
Are you using same chip part nubmer? or different?
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| Reply #7
merlinkv
Spain
6 Posts |
Posted - 11/21/2011 : 12:03:39
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Hi,
I made all test using 24 different EPROMs AMD 27C400 the only difference between EPROMs are the speeds: 100 & 120ns.
In all chips I can write with 100% success the next:
- Buffer or file with "bad" code
- Buffer filled by "00"
- Buffer filled by "FF"
In all chips I cannot write any image of my ROMs or any code different than "00", "FF" or the readed "bad" code....
All chips are good erased before writing and Blank Check is OK..... 24 different EPROMs are damaged? Also I made other tests with 8 EPROMs 27C800 for 1Mbyte ROMs... the same problem.... |
Edited by - merlinkv on 11/21/2011 12:20:06 |
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| Reply #8
ZLM
2937 Posts |
Posted - 11/26/2011 : 19:20:38
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| It looks like the adapter may have some problem on data bus. Please contact support@mcumall.com for warranty help. |
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| Reply #9
kire_online
Australia
9 Posts |
Posted - 11/28/2011 : 16:51:53
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Adapter might be faulty, mine was also faulty, I found the solder bridge and removed it, now it reads ROM correctly with checksum.
Mcumall support is responsive, but if you'd like some feedback, your quality control is very bad, please test the adapters before shipping to customers. |
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| Reply #10
ZLM
2937 Posts |
Posted - 11/28/2011 : 21:29:22
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| Each adapters should be tested before it shipped. This is an individual case. |
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| Reply #11
merlinkv
Spain
6 Posts |
Posted - 12/11/2011 : 03:18:17
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quote:
Originally posted by ZLM
Each adapters should be tested before it shipped. This is an individual case. It may be a mistake suring the shipping process.
It seems like "two individual" cases...... |
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Topic |
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GQ-4X Cannot program 
