Changes
External 8bit Printer Port from ''Amstrad Action Issue 38'' (November 1988).
== Description ==
This is a rather bizarre [[8bit Printer Ports|8bit Printer Port]] solution. Aside from the 8th data bit, it doesn't come up with any other extras: Data is only one-directional, and only Strobe and Busy control signals are implemented.
Compared with the much older single-wire [[Happy Computer 8bit Printer Mod]] (1985), the Amstrad Action approach is terribly overcomplicated.Another downside is that the external circuit isn't backwards compatible with normal 7bit printer software. == Technical == Connects to the expansion port. Uses six TTL chips (74HC133, 74LS138, 74LS273, 74LS241, 74LS02, 74121), 4 resistors, 1 capacitor, plus some connectors. Port Bits Expl. FBF8h N/A Strobe (W) FBF8h Bit0 Busy (R) FBF9h Bit0-7 Data (W)Writing any value to port FBF8h issues a short Strobe signal (the length of the signal is same as /IORQ ORed with /WR). == Scanned Article ==
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File:8bitPrinterAmstradActionIssue38page57.jpg
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[[Category:Printers and printer ports]] [[Category:DIY]]
