diff --git a/README.md b/README.md index 82f2516..b3aba7a 100644 --- a/README.md +++ b/README.md @@ -1,10 +1,16 @@ -# Micro-SCI / Franklin Apple ][ Floppy Drive Controller +# Weyoun -This is a clone of the Micro-SCI / Franklin floppy drive controller. +![usci](usci.png?raw=true "usci") -v0.1 is a direct clone, reverse-engineered from a Micro-SCI board. It was cross-checked with a Franklin-branded board, as well as the (belatedly discovered) official Franklin schematic (included in doc/service_and_schematics.pdf) +Weyoun is a clone of the Micro-SCI / Franklin floppy drive controller. -v0.2 has the following enhancements over the original design: +## Features + +## Revision history + +Weyoun 1 was a direct clone, reverse-engineered from a Micro-SCI board. It was cross-checked with a Franklin-branded board, as well as the (belatedly discovered) official Franklin schematic (included in doc/service_and_schematics.pdf) + +Weyoun 2 had the following enhancements over the original design: * the 2708 EPROM has been replaced with a more-common 2716/2732 EPROM * decoupling capacitors have been added @@ -15,7 +21,7 @@ v0.2 has the following enhancements over the original design: * ground pours used to increase operational stability * support for using Floppy Emu in dual-drive emulation mode with one cable -v0.3 has the following enhancements over v0.2: +Weyoun 3 has the following enhancements over Weyoun 2: * a 74LS245 octal buffer has been added to the data bus, to facilitate the use of a no-slot clock under the firmware EPROM * the EPROM has been changed from 2716/2732 to 2764/27128/27256 to allow a no-slot clock to be placed in the socket without modification @@ -25,8 +31,6 @@ v0.3 has the following enhancements over v0.2: Firmware images can be built via the Makefile in the firmware subdirectory. The build framework requires cc65. -![usci](usci.png?raw=true "usci") - ## EPROM bank select switches (J4) * 1:off 2:off - firmware "put jumpers here" splash screen (0x0300) @@ -49,6 +53,5 @@ Firmware images can be built via the Makefile in the firmware subdirectory. The ## Construction notes -* J3 can be omitted if this controller is used with a FloppyEmu -* All discrete logic ICs (except U15, the 74LS373) can be CMOS (74ACT, 74HCT). As is unfortunately usual with the Apple ][, U15 must be LS due to timing issues. -* if CMOS logic is used, then Q1/R6/R7 can be omitted -- the entire logic array can remain powered up at all times. Connect pads 1 and 3 on the Q1 footprint. +* The second floppy drive header (J3) can be omitted if this controller is used exclusively with a FloppyEmu. Populate R11 and connect pins 1 and 2 on J7. +* All discrete logic ICs (except U19, the 74LS245) should be CMOS (74ACT, 74HCT). As is unfortunately usual with the Apple ][, U15 must be LS due to timing issues.