wyerd Posted January 28, 2015 Share Posted January 28, 2015 I ran the RAM test to see if everything was OK after blowing the PEB PSU and installing a new one using an AT PSU. This is the result with the 8x32K card installed. Have I got some dud memory somewhere? Thanks. Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted January 28, 2015 Share Posted January 28, 2015 I think it is within the realm of possibility. Those address have commonality in addressing and value so it is probably just a single chip that got popped. If the value was different each time I would think that an address buffer got blown. Anyone else with thoughts? Quote Link to comment Share on other sites More sharing options...
wyerd Posted January 28, 2015 Author Share Posted January 28, 2015 Interestingly, the 8x32K memory expansion light doesn't come on during the test. Should it? Quote Link to comment Share on other sites More sharing options...
Willsy Posted January 29, 2015 Share Posted January 29, 2015 Interestingly, the 8x32K memory expansion light doesn't come on during the test. Should it? Those LOC (location) addresses are in ROM. Weird. The 32k is mapped from >2000 to >3FFF and >A000 to >FFFF. Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted January 29, 2015 Share Posted January 29, 2015 Those LOC (location) addresses are in ROM. Weird. The 32k is mapped from >2000 to >3FFF and >A000 to >FFFF. I missed that. I was thinking these addresses were offsets, but that makes little sense. Quote Link to comment Share on other sites More sharing options...
Omega-TI Posted January 29, 2015 Share Posted January 29, 2015 Interesting, I just use the CorComp version of the test, which I pass, because with the TI version I get the mess viewed below. FWIW - The 32K light does not come on with mine either, although it does with the CorComp test. Quote Link to comment Share on other sites More sharing options...
Asmusr Posted January 29, 2015 Share Posted January 29, 2015 Those LOC (location) addresses are in ROM. Weird. The 32k is mapped from >2000 to >3FFF and >A000 to >FFFF. How can it check the ROM without having another known good copy? Quote Link to comment Share on other sites More sharing options...
+mizapf Posted January 29, 2015 Share Posted January 29, 2015 IIRC the last two bytes are a checksum. Quote Link to comment Share on other sites More sharing options...
Willsy Posted January 29, 2015 Share Posted January 29, 2015 How can it check the ROM without having another known good copy? indeed. Makes no sense at all to me! Quote Link to comment Share on other sites More sharing options...
+mizapf Posted January 29, 2015 Share Posted January 29, 2015 Well, as I said (also see e.g. TI Intern), there is a checksum at the end of the ROM (also at the end of each GROM), so all you do is to sum up all values and check against that value. Proper way to check whether the ROM is good. Quote Link to comment Share on other sites More sharing options...
Tursi Posted January 30, 2015 Share Posted January 30, 2015 The Diagnostics Cartridge RAM test tests VDP RAM, not CPU. 1 Quote Link to comment Share on other sites More sharing options...
Omega-TI Posted January 30, 2015 Share Posted January 30, 2015 The Diagnostics Cartridge RAM test tests VDP RAM, not CPU. 1 Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted January 30, 2015 Share Posted January 30, 2015 Interesting, I just use the CorComp version of the test, which I pass, because with the TI version I get the mess viewed below. FWIW - The 32K light does not come on with mine either, although it does with the CorComp test. That looks like a VDP RAM issue... Quote Link to comment Share on other sites More sharing options...
wyerd Posted January 30, 2015 Author Share Posted January 30, 2015 Interesting, I just use the CorComp version of the test, which I pass, because with the TI version I get the mess viewed below. FWIW - The 32K light does not come on with mine either, although it does with the CorComp test. My CorComp test passed as well with the 32K light on. I then took option 2 of the TI RAM test with address and it passed after displaying weird multicolour graphics. So do I have a VDP RAM issue? Quote Link to comment Share on other sites More sharing options...
wyerd Posted January 30, 2015 Author Share Posted January 30, 2015 I found in the TI diags, Option 9, there's a VDP RAM test. It ran for an hour with the odd character floating around the screen now and again, but nothing else happened until I pressed the enter key as I got bored waiting. So I'm not sure what the 1st post really means. Quote Link to comment Share on other sites More sharing options...
Tursi Posted January 30, 2015 Share Posted January 30, 2015 If everything is working (particularly try TI BASIC and try some larger programs out, if you can), I wouldn't be too worried. I don't have 100% confidence in the Diagnostics cart on the 4A... Quote Link to comment Share on other sites More sharing options...
jens-eike Posted January 30, 2015 Share Posted January 30, 2015 The Test program logic in the original post may have a flaw(?). When testing VDP-RAM and not taking into account the auto-incrementing of VDP addresses, that could give the above pattern. But then, it should give the same error on all locations... Quote Link to comment Share on other sites More sharing options...
kl99 Posted January 31, 2015 Share Posted January 31, 2015 I have the EB27 cartridge as well and run the tests with a real PEB with standard 32K TI expansion. I was not able to get such results nor find out what kind of test results we actually see here. Which test have you executed? ) MAIN MENU: 3 RAM TEST- 1 FOR CHECKER BOARD TEST - 2 TO TEST WITH ADDRESS - 3 TO INPUT TEST PATTERN ) MAIN MENU: 9 MAINTENANCE- 5 VDP RAM Quote Link to comment Share on other sites More sharing options...
Tursi Posted February 1, 2015 Share Posted February 1, 2015 The diagnostics cart does report success on a normal console, I don't believe it has a bug in that case. I just wouldn't use it as my ONLY test when it reports a failure - try other things too. Quote Link to comment Share on other sites More sharing options...
wyerd Posted February 1, 2015 Author Share Posted February 1, 2015 The diagnostics cart does report success on a normal console, I don't believe it has a bug in that case. I just wouldn't use it as my ONLY test when it reports a failure - try other things too. It's been running TI Invaders from the Extended Basic v2.7 cart for the last 2 hours without any issues, so I can only assume that everything's ok. Time will tell. Quote Link to comment Share on other sites More sharing options...
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