Search found 558 matches

by tcat
Tue Oct 01, 2019 12:02 pm
Forum: Hardware
Topic: DIY Fpu Unit for STFM
Replies: 28
Views: 3717

Re: DIY Fpu Unit for STFM

Hi Nasta, Thank you for taking your interest, it's just fun and toy albeit for `non-QL' platform. Currently working on FPU tests with the aim to get this completed. [a] Inline assembly macros - based on Motorola AN947 [b] F-line emulation trap - ditto [c] FPU Library linkable against "math.h&qu...
by tcat
Mon Sep 30, 2019 8:23 am
Forum: Hardware
Topic: DIY Fpu Unit for STFM
Replies: 28
Views: 3717

Re: DIY Fpu Unit for STFM

Hi, Cannot help thinking more about $Fxxx and $Axxx. The emulation can be achieved through exception trap vectors. As on plain MC68000/8 $Fxxx and $Axxx machine code instructions simply do not exist. So the attempt excecuting them leads to an exception that can be caught by a handler. The respective...
by tcat
Thu Sep 26, 2019 3:14 pm
Forum: Hardware
Topic: DIY Fpu Unit for STFM
Replies: 28
Views: 3717

Re: 74HCxx vs 74LSxx

a graphics GPU co processor ATARI had this idea with their BLITTER chip, offering raster operations and graphics primitives. These instructions are encoded as $Axxx, A-Line instructions so to speak. Providing emulation under TOS, and some 600-700% boost on systems with the chip fitted in the socket...
by tcat
Thu Sep 26, 2019 8:07 am
Forum: Hardware
Topic: DIY Fpu Unit for STFM
Replies: 28
Views: 3717

Re: 74HCxx vs 74LSxx

Hi, Studying now FPU instruction encoding, 16 bit field constists of 1111 - $F bbb - Coprocessor ID bbb- Instruction Type bbbbbb - <ea>, CC, ... type dependant I can see some interesting points here. $Fxxx, F-Line instructions, emulating co-pro on the systems w/o FPU, or propagating directly to the ...
by tcat
Mon Sep 23, 2019 1:02 pm
Forum: Hardware
Topic: DIY Fpu Unit for STFM
Replies: 28
Views: 3717

Re: 74HCxx vs 74LSxx

Hi Derek, Yes, very good points. I asked about ATARI socketed MC68000 cpu boards, have learnt exist seldomly and I did not have better idea but connecting cpu with wires, as extracting the cpu in a single piece, not easy, needing skills and special gadgets so I was told. Honestly was surprised I mad...
by tcat
Fri Sep 20, 2019 10:58 am
Forum: Hardware
Topic: DIY Fpu Unit for STFM
Replies: 28
Views: 3717

Re: 74HCxx vs 74LSxx

Hi,

As my soldering is not very neat, I am no way sure I had it functional. I run this simple test that was coded by a German ATARI branch years ago.

sfp004-test-2.JPG
Running FPU math test

This may be an indication, it hopefully works?
Thomas
by tcat
Thu Sep 19, 2019 1:11 pm
Forum: Hardware
Topic: DIY Fpu Unit for STFM
Replies: 28
Views: 3717

Re: 74HCxx vs 74LSxx

Hi, I have only a simple `pistol' soldering iron, and I am not very skilfull with it. This is what I have, ICs populated in the sockets, VCC/GND sourced around PSU connector. GEM-BENCH reports some 1400% on FPU math test, while SYSINFO reports NO-COPROCESSOR fitted. What does it actually mean? Many ...
by tcat
Mon Sep 09, 2019 11:22 am
Forum: Hardware
Topic: DIY Fpu Unit for STFM
Replies: 28
Views: 3717

Re: 74HCxx vs 74LSxx

Hi, No idea it will work in the end, but this is how it may fit inside my STFM machine. P1 should connect to CPU pins using ribbons, at least that is the idea so far, but there is RP7 red component getting in the way on one CPU side!!! Inevitably the ribbon will partly cover CPU from top, any precau...
by tcat
Sat Aug 17, 2019 5:14 pm
Forum: QL Emulation
Topic: uQLx 2018a
Replies: 25
Views: 4624

Re: uQLx 2018a

Hi, Still thinking about zoom>1, this is when the emulator window does not get updated properly. On my further looking into, with zero X-Windows knowledge, this is what I see happening. In `xql.c', `x.c' there is XposeEvent, looks like an event loop, from within `redraw-screen()' is called. In `redr...
by tcat
Fri Aug 16, 2019 12:42 pm
Forum: Hardware
Topic: DIY Fpu Unit for STFM
Replies: 28
Views: 3717

Re: 74HCxx vs 74LSxx

Hi, Just spotted the application note `AN947', pointed a few posts above, is missing appendices B,C. Anyone having the full document? EDIT The document I have is `AN947_REV0.PDF', I guess REV0 stands for revision 0. It just happens to miss some pages at the end, containing appendices B,C. It is Moto...