Suska board

[Cyprian]

if necessary, we can prepare a small AUTO .PRG that will perform a new memory size check and set the OS variables accordingly

[exxos]

if necessary, we can prepare a small AUTO .PRG that will perform a new memory size check and set the OS variables accordingly

That would be cool. I never thought of doing that.

Potentially I could build a new build of TOS206 to support it, just I am not familiar with assembly to make those changes.

I guess the problem is there isn't any way of actually testing what TOS does currently. I don't have any simple alt-ram boards to try. Though I guess if alt-ram is enabled on boot, TOS should write a pattern to which could be read back.. Problem being the video will not be accessible. But I don't have time to get sidetracked to another project right now anyway

[Cyprian]

Potentially I could build a new build of TOS206 to support it, just I am not familiar with assembly to make those changes.

nice idea, there is a source code for TOS 1.x / 2.x on Thorsten Otto Github, and we could try to extend that memory check.
Also also EmuTOS could handle more ST-RAM memory.

[Cyprian]

As
MMU and SHIFTER in FPGA?

It's already been done.
https://www.exxosforum.co.uk/forum/view ... 660#p77579
https://www.exxosforum.co.uk/forum/view ... =10#p33827

ah, ok,
great

[exxos]

A bit further down the code it does mention ST RAM in the TT..

Code: Select all

/* =========================================================================== */
/* ==== memconf for TT ======================================================= */
/* =========================================================================== */
/*
 * The following configurations are valid for ST-RAM in a TT, listed as
 * total RAM (motherboard RAM + optional daughterboard RAM):
 *  2MB (2MB + 0MB), 4MB (2MB + 2MB), 10MB (2MB + 8MB)
 * [According to the TT rev B MCU functional description, it is also
 * possible to have 8MB (8MB + 0MB) and 10MB (8MB + 2MB) configurations,
 * but I have not seen this.]  When an 8MB board is present, it is always
 * mapped to the first 8MB of memory.
 *
 * Systems with only 2MB boards require a memcntlr value of 0x05; systems
 * with an 8MB board require a memcntlr value of 0x0a.  We detect which
 * size of board is in low memory by assuming an 8MB board, then checking
 * for different memory addresses mapping to the same physical address.
 *
 * rfb (sep/2016)
 */
        move.w    #$0005,d6           /* assume 2MB board */
        move.b    #$0A,(memconf).w  /* set memory controller for 8MB */
        moveq.l   #0,d0
        move.l    d0,($00001008).w    /* zero out test addresses */
        move.l    d0,($0000100C).w
        move.l    #$06161964,d0       /* write test value #1 to an address */
        move.l    d0,($00000008).w    /*  that may be mapped into test address #1 */
        cmp.l     ($00001008).w,d0    /* did test address #1 get updated? */
        bne.s     set_8MB             /* no, must be an 8MB board */
        move.l    #$04251987,d0       /* yes, repeat with test value #2 to be sure */
        move.l    d0,($0000000C).w    /* did test address #2 get updated? */
        cmp.l     ($0000100C).w,d0    /* yes, use the 2MB memcntlr value  */
        beq.s     set_2MB
set_8MB:
        move.w    #$000A,d6           /* set 8MB memcntlr value */
set_2MB:
        move.b    d6,(memconf).w    /* update memcntlr */
#endif

[Cyprian]

There is mem check code in TOS 1.x: https://github.com/th-otto/tos1x/blob/4 ... tup.S#L344

It looks like it's being made to death... I mean the bus error.

Therefore probably there is no need for any TOS 1.x modifications, and all that is required is to generate the bus error above ST-RAM

[exxos]

There is mem check code in TOS 1.x: https://github.com/th-otto/tos1x/blob/4 ... tup.S#L344

It looks like it's being made to death... I mean the bus error.

Therefore probably there is no need for any TOS 1.x modifications, and all that is required is to generate the bus error above ST-RAM

Good find thanks. I always understood it went to bus error, but couldn't be sure over 4MB.