From 7fd84e59a1b79f0621a0dc93e46968be496860c2 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Fri, 17 Jul 2015 23:25:00 +0100 Subject: [PATCH] trs80: update README --- Kernel/platform-trs80/README | 38 +++++++++++++++++++++++++++++++++--- 1 file changed, 35 insertions(+), 3 deletions(-) diff --git a/Kernel/platform-trs80/README b/Kernel/platform-trs80/README index 165f2c20..6234f4e5 100644 --- a/Kernel/platform-trs80/README +++ b/Kernel/platform-trs80/README @@ -12,12 +12,15 @@ Emulator Bugs: PC -= 2". FUZIX doesn't do any overlapped LDIR tricks so shouldn't be affected. + The interrupt flags are misemulated. A patch for this is in the + Fuzix tree and is needed to run Fuzix on xtrs/sdltrs + Requirements: 128K RAM fitted Hard disk drive (will be used for swap), or a suitable memory expander board could be used with a bit of tweaking (or both!) - *** NOTE: the current code will simply swap blindly all over the first - hard disk *** + (The hard disk code should work with the Lo-tech IDE adapter but + this has yet to be confirmed) Memory Map: Base memory 0-FFFF (with a fair bit of slack) is used for the kernel @@ -42,7 +45,7 @@ Drivers: Floppy and Hard disk are done and minimally tested Floppy drivers do not yet deal with double sided disks or sd/dd media detection - Hard disk needs to read block 0, and handle partitions of some form + Hard disk reads block 0, and handle partitions of some form including finding where 'swap' lives Adding Support For Other Banked RAM: @@ -91,3 +94,32 @@ To set up for hard disk, create a hard disk with the xtrs tools and You will still need a boot floppy at this point but just boot with device 0 (or hit return). Swap is configured to be on the end of the hard disk + + + +Banking Models + +Currently Supported: + TRS80 model 4 with inbuilt memory bank switching + +In Progress: + Port 0x94 modification to add extra internal RAM to a 4 and 4P + +Not Yet Started: + "Selector" for Model 1. Port 31 allows memory reshuffling away from +the model 1 default. Either the upper or lower 32K is switchable but not +both at once. bits 4/5 control the selection between a further 4 32K banks. +Also needs model 1 support adding of course. + + +Documentation Needed: + Various other RAM banking boards (AlphaTech and the like) + + HD64180 mods with more RAM (these are I suspect almost a different port) + (XLR8R etc) + +Not Usable: + Various model 1 interfaces that provide 64K RAM or near 64K RAM. Not +enough for Fuzix on Z80. Possibly enough for UZI with a hard disc. + + LNW80 model II (same problem - 64K only) -- 2.34.1