sutela@polaris.utu.fi (Kari Sutela) (12/07/90)
I'm having some trouble with my SupraRAM memory expansion. My hardware configuration is: a rather old Amiga500 (with A501), a Supra 30 MB harddrive with a Supra interface. The interface and the harddrive are about two years old. A couple of months ago I bought the 2 MB memory expansion card which fits inside the Supra interface. My problem is that the memory expansion causes random crashes --- initially I didn't notice this as most of the programs I ran didn't need the expansion (and I didn't FastMemFirst in my startup-sequence). Anyway, recently I have been using some programs which need the memory expansion (AmigaTeX, for example) and I have found that the memory expansion is unreliable. I have tested my hardware quite extensively and I found that disabling the SupraRAM expansion removes the symptoms --- for example, running a program in slow/pseudofast memory is OK, while the same program in fastram crashes the system. Despite this fact, the SupraRAMTest program can find no faults with the memory expansion (and I have let it run for hours). The most strange thing is that the problem doesn't occur constantly. Recently, I had three weeks during which the memory expansion worked perfectly, but one evening the symptoms reappeared. I hadn't made any modifications to my system (no new software installed, no modifications to startup-sequence, etc.) but some things which had worked the previous day, failed completely. For example, at bootup I would give the following commands: cd tex:mysource latex myreport ; latex is an alias for "tex &lplain" which had worked the previous day (and no, I didn't modify myreport) but now gives me a Guru. I would send my system to my dealer's for repairs but there is some work that I absolutely must complete before I can do it. On the other hand, I have heard about indentical problems with an A590 which has been twice at a repair center without any success (the service-people could find no fault). There's yet another strange symptom: when a program is running in fastmem its graphic operations cause some strange high-pitched, 'chirping' sound from the harddrive (or the box containing it). For example, if I run TxEd+ (a text editor) in chip or pseudofast memory scrolling text is noiseless --- but if I run it in expanded memory every scroll-operation causes a brief 'chirp' from the harddrive. The only explanation for this that I can think of is the fact that the harddrive-box contains the powersupply both for the harddrive and the interface with the memory expansion. Could the use of expanded memory be over-taxing the power-supply (and would this 'chirp' be a symptom of some problems with the PS)? Any suggestiond would be greatly appreciated. Are there any obvious things that I might have overlooked? How could the memory expansion work perfectly for weeks and then suddenly start guruing (and then again, after a few days it works perfectly)? Thanks in advance, -- Kari Sutela sutela@polaris.utu.fi