En:RE: Parallel Port Ram Tester from Brazil!
Hello Folks ! The first part of the project, will make a Test Pattern, once the RS232 does not have enough speed to make a the Speed Test. Most of SRAM memories fail at this point... It consists on fill all addresses with 0s, 1s and pattern like 0000000000 0000000001 0000000010 0000000100 0000001000 0000010000 0000100000 0001000000 0010000000 0100000000 1000000000 0100000000 0010000000 0001000000 0000100000 0000010000 0000001000 0000000100 0000000010 0000000001 And repeat at inverse way (0s in place os 1s and 1s in place of 0s) The second part of the project, I'm planning to make on clock circuit (up to 20MHz) to make the Speed Test, filling all addresses with 0s and another test filling with 1s. The software control, will be another important part of this project. I hope to share experiences with you guys, and ALL comments will be very welcome !!! I'm studing PIC microcontroles, and soon I hope to have one PCless tester :) Thank you JosÈ Luiz Martins De:"joemagiera" Para: CÛpia: Data:Mon, 29 Dec 2003 17:11:04 -0600 Assunto:RE: Parallel Port Ram Tester from Brazil!
Hi Luiz,
Welcome to our list! I am extremely interested in this project, especially if it will thouroughly test 4116 and 4164 RAM. Any chance I could pay you to build an extra one for me?
Are you planning on having the tester test RAM at different speeds also?
Joe joemagiera@ameritech.net
-----Original Message----- From: owner-techtoolslist@flippers.com [mailto:owner-techtoolslist@flippers.com]On Behalf Of John Robertson Sent: Monday, December 29, 2003 03:21 PM To: techtoolslist@flippers.com Subject: RE: Parallel Port Ram Tester from Brazil!
pc2jamma@terra.com.br
Nice guy, he just emailed me the JPG and it is now on the FTP server...
John:-#)#
At 11:28 AM 29/12/2003, joemagiera wrote:
Can you please post Luiz email address? Would like to contact him of
Joe joemagiera@ameritech.net
-----Original Message----- From: owner-techtoolslist@flippers.com [mailto:owner-techtoolslist@flippers.com]On Behalf Of John Robertson Sent: Monday, December 29, 2003 01:00 PM To: techtoolslist@flippers.com Subject: Parallel Port Ram Tester from Brazil!
One of our new members (Luiz) was attempting to post a note on a project of his, but it was too long (embedded JPG) and I think he might be on vacation (or something) so I'll edit and post it for him...(I've put his schematics in their own folder on the ftp site (RamTester)).
Unfortunately I have been unable to extract the JPG from his huge post...hoping he'll send it to me!
John :-#)#
-----------------------(original)--------------------------------- --------------
Hello Folk!
I decide to start building one PC (Parallel port) Based SRAM Tester, after some attempts to use old tester on fast PCs with no success, and due to prohibitive prices of modern
one. For me,
in Brazil, it costs about 2,000 Dollars !!!! The first part of this project is a simple 2114 Tester, and the next step will be accept 5101, 4116, 6116 and finally 6281. My target is build one TTL and CMOS Tester as well.
I'll share with you guys this project, and I'll be very glad to hear suggestions and answer all your questions. Attached, you are receiving it's schematics, and this weekend I'll write it's code.
I did this project as simple as possible, using one CD4040 (12 binary Counter) to generate the address line, one 74LS245 (Octal Bus Transceiver) as data buffer and to protect the PC's RS232 port.
Thank you for your t reading this e-mail, and I'm sorry for the grammatical errors !
Luiz Martins Paulo / Brazil
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-----Original Message----- From: owner-techtoolslist@flippers.com [mailto:owner- techtoolslist@flippers.com] On Behalf Of John Robertson Sent: Monday, December 29, 2003 9:49 PM To: techtoolslist Subject: Re: En:RE: Parallel Port Ram Tester from Brazil!
What a great project!
The RAM pattern test used by Fluke might be of interest here. It will identify stuck address bits - but I have no idea of exactly the process used to generate the Fluke RAM test. Perhaps someone else here might have some algorithms that they can recommend?
I was just testing an Asteroids today and the 9010 showed a DCD error (was a failing A10 on the Vector RAM) - which proved to be a problem with a replacement socket. RAM tests must be able to check that address lines are all working as well as the data can be read out...so offset the pattern by one bit for each address line to make sure you pick up these errors!
DCD error identification is very useful. I find that a lot of the RAMs that fail (besides an all-out failure) fail on a DCD error. Your algorithm will have to do something like start with an address range that is all 00 (or all FF... ) and then write something like $AE to a given address. Then it'll need to test each address line (XOR 1 into each bit of the address?) and then read from that address. If it reads your test pattern in any of the other addresses, then you have a decoding error. Finally, you'd want to write back to your test address $00 to clear it and move onto the next test address. DCD testing can probably be done just by testing addresses: 0000 0000 0000 0001 0000 0010 0000 0100 0000 1000 0001 0000 0010 0000 0100 0000 1000 0000 for a real quick test. A through test would be to test it on each individual address. The Fluke 9100A manual may give you some ideas of tests. Other tests to consider are "burn in" repetitive tests that you could leave running for a while. Ideally, I'd like to hook up a lot of chips and then run the test. Possible? --James Bright www.QuarterArcade.com Restored Arcade Games for your Home If you ever want to (un)subscribe yourself with TTL, you can send mail to: <Majordomo@flippers.com> with the following command in the body of your email message: (un)subscribe techtoolslist or from another email account, besides xxx@yyy.com: (un)subscribe techtoolslist xxx@yyy.com
participants (3)
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James Bright -
John Robertson -
pc2jamma