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Qwerty
Joined: 20 May 2005
Posts: 3141
Location: Germany
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 Posted: Fri Oct 06, 2006 1:31 pm Post subject: Intel D27513 EPROM ??? |
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Hi,
I have found this very odd EPROM chip in the pile of D27512.
I have never seen such type before. What does D27513 mean ? Is it a 513 KBit EPROM ?! |
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CPUShack
Joined: 16 Jun 2003
Posts: 34259
Location: State of Jefferson, USA
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chip68
Joined: 19 Oct 2004
Posts: 1024
Location: Central Pennsylvania
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| Posted: Fri Oct 06, 2006 1:41 pm Post subject: |
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16K x 8 x 4, 200ns, 12.5V program. Second-sourced by Atmel.
- CMW |
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CPUShack
Joined: 16 Jun 2003
Posts: 34259
Location: State of Jefferson, USA
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| Posted: Fri Oct 06, 2006 1:45 pm Post subject: |
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err yah lol paged EPROM, as opposed to most that werent, 27257, and 27513 as well as the 27011 were paged
I THINK the 2763 may have been but alas I have no reference to it in any of my databooks
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chip68
Joined: 19 Oct 2004
Posts: 1024
Location: Central Pennsylvania
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| Posted: Fri Oct 06, 2006 1:54 pm Post subject: |
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Nor in mine. Strange.
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Qwerty
Joined: 20 May 2005
Posts: 3141
Location: Germany
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| Posted: Fri Oct 06, 2006 2:19 pm Post subject: |
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Thanks for your replies!
Could you tell me what "paged" EPROM is ?
I don't know much about the internal architecture of EPROMs.  |
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CPUShack
Joined: 16 Jun 2003
Posts: 34259
Location: State of Jefferson, USA
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| Posted: Fri Oct 06, 2006 3:27 pm Post subject: |
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think of it this way
a 27512 has 64k 8bit bytes
so it has an 8 bit data bus and a 16 bit address bus
a 27513 has 4 sets (or pages) of 16k 8bit bytes
so it has an 8 bit data bus and a 14 bit address bus as well as 2 lines to select which PAGE that address goes to. functionally its not much different really
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Bruce Mardle
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| Posted: Thu Nov 05, 2015 1:11 pm Post subject: 27513 paged EPROM |
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| CPUShack wrote: | think of it this way
a 27512 has 64k 8bit bytes
so it has an 8 bit data bus and a 16 bit address bus
a 27513 has 4 sets (or pages) of 16k 8bit bytes
so it has an 8 bit data bus and a 14 bit address bus as well as 2 lines to select which PAGE that address goes to. functionally its not much different really |
Ah! But the cunning part is that the page is selected by writing to the 2 page-select bits. So you can squeeze 64KiB of ROM into 16KiB of your (presumably small) address space.
(I hadn't heard of these till I saw a UTSource ad for them.) |
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rjluna2
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Location: Hiram, GA, USA
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rjluna2
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