From another thread, I think Juror22 is looking for Pseudo-Static RAM chips. Not regular FPM DRAM chips.
Juror, I have over 100 of the Hitachi HM658512ALFP on hand. These are 512K-word X 8-bit chips. I expect these are the same as the Hitachi 658128ALFP-10 but with four times the density.
Those websites you're finding are all irritating. They'll ask you to request a quote, and then ask you to pick a target price. And either your target price is too low and they never respond, or it's too high and you overpay, but the quantity you listed is too low to meet their minimum, so they won't sell it to you anyway.
That said, I'd try questcomp.com if you really need the '128' version. They seem to have some older, harder to get parts with actual prices listed on their website. Some parts come up as "call for quote", but many of them have actual prices listed.
I just watch Ebay for interesting memory chips, but that's how I ended up with an attic full of stuff like over a hundred of a memory chip I'll never use unless I build a memory upgrade for a computer I don' t have...
If you'd like me to email you the datasheet for the chips I have, PM me your email address.
Oh, never mind, I just remembered that I sold you caps a week ago. I've emailed you the datasheet.
To answer your base question, there is not a systematic naming convention for memory chips. Numbers preceeded by a dash, after the main part number usually indicate the speed rating of the parts. And some chip manufacturers used 256, 1000, and 4000 to indicate those sizes of parts in kilobits. But others used things like 1001, or 4004 and 4001, where sometimes (but only sometimes) the trailing 1 or 4 indicated the bit width of the device.
Really, one must get the datasheet for any part one is interested in and read it, to determine what a part really is.
And I just hunted down the HM658128 datasheet and emailed you that for comparison. Googling for datasheets tends to bring up all those irritating chip merchants who don't actually have any stock, nor datasheets, but all want you to fill in an RFQ. When searching for datasheets, datasheetarchive.com tends to be your best bet.
Juror, I have over 100 of the Hitachi HM658512ALFP on hand. These are 512K-word X 8-bit chips. I expect these are the same as the Hitachi 658128ALFP-10 but with four times the density.
Those websites you're finding are all irritating. They'll ask you to request a quote, and then ask you to pick a target price. And either your target price is too low and they never respond, or it's too high and you overpay, but the quantity you listed is too low to meet their minimum, so they won't sell it to you anyway.
That said, I'd try questcomp.com if you really need the '128' version. They seem to have some older, harder to get parts with actual prices listed on their website. Some parts come up as "call for quote", but many of them have actual prices listed.
I just watch Ebay for interesting memory chips, but that's how I ended up with an attic full of stuff like over a hundred of a memory chip I'll never use unless I build a memory upgrade for a computer I don' t have...
If you'd like me to email you the datasheet for the chips I have, PM me your email address.
Oh, never mind, I just remembered that I sold you caps a week ago. I've emailed you the datasheet.
To answer your base question, there is not a systematic naming convention for memory chips. Numbers preceeded by a dash, after the main part number usually indicate the speed rating of the parts. And some chip manufacturers used 256, 1000, and 4000 to indicate those sizes of parts in kilobits. But others used things like 1001, or 4004 and 4001, where sometimes (but only sometimes) the trailing 1 or 4 indicated the bit width of the device.
Really, one must get the datasheet for any part one is interested in and read it, to determine what a part really is.
And I just hunted down the HM658128 datasheet and emailed you that for comparison. Googling for datasheets tends to bring up all those irritating chip merchants who don't actually have any stock, nor datasheets, but all want you to fill in an RFQ. When searching for datasheets, datasheetarchive.com tends to be your best bet.