Identifying parts on a VT100 logic board

From: Pete Turnbull <>
Date: Sat Mar 10 08:20:14 2001

On Mar 10, 12:41, Paul Williams wrote:

> There are four socketed chips together, labelled E40, E45, E52 and E56.
> Does anyone have the schematics and know what these contain?

They're the VT1xx code ROMs. In a VT100, they are contain ROMs with part
numbers 23031-E2, 23032-E2, 23033-E2, and (surprise, surprise) 23034-E2.
 In a VT100-WC, -WK, or -AC, they contain 23095-E2, 23096-E2, 23139-E2,
23140-E2; the -WC and -WK variants also have an extra character ROM,
23094-E2. A VT125 or VT105 should have the same as a plain VT100 except
that the 23031-E2 is replaced with a 23061-E2.

> The fourth chip, E45, is labelled differently on the two boards
> Board 1. Signetics K8340 / CN7295N / 23-033E2-00 / (c) DEC 1978
> Board 2. [logo S] 8015E / C48008 / 23033E2
> I assume that 23033E2 is DEC's part number, but I can't find references
> for either 8340 or 8015. Is this another ROM?

Yes, 23 means a mask ROM, the next three digits are the ROM code number,
and the E2 is the size (2K in this case; E3 is 4K, E4 is 8K, etc). 8340
and 8015 are probably the date of manufacture.

Pete						Peter Turnbull
						Network Manager
						Dept. of Computer Science
						University of York
Received on Sat Mar 10 2001 - 08:20:14 GMT

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