Victor Trucco announced MSX-SM | MSX Resource Center (Pagina 4/11)

Ascended (10767)

25-06-2019, 18:18

What about moving the disk ROM from slot 3-2 to 0-1? I think having a disk ROM in slot 0 is also a fairly common thing, so that should work without issues...?

Van KdL

Paragon (1450)

25-06-2019, 18:50

There is a smart command that turns slot 0 into non-expanded, I should give up the possibility of running the games that require this situation. So I prefer to have an external slot 0-1 with some compatibility issues rather than a limited machine in the capability.

The practice of dynamically changing slots is already widely used and, regardless of the default situation, I think it is the best solution.

However, it is very important that the connections relating to the 3rd slot are distinct from the 1st and 2nd slots on the pcb and inside the firmware, otherwise I will not be able to redesign anything on it.

Van ducasp

Paladin (680)

25-06-2019, 20:30

KdL wrote:

Grauw wrote:

Slot 0 can cause problems with certain types of ROMs cartridges, because either the BIOS or DOS (or both) can not select subslots from slot 0 in page 0 (iirc)... So for example the Yamaha SFG-05, which uses page 0, wouldn’t work there.

If one of the ROMs currently in slot 3 can work in slot 0-1 (I think 3-2 or 3-3 are candidates), it may be better to move it and offer a free general purpose subslot in slot 3 instead. Yamaha has the module side slot mapped to slot 3-3 on their machines.

I had already evaluated this situation as well. I had to move XBASIC from slot 0-1 to slot 3-3 to allow some games to work. I could create a new smart command to use the 3rd slot dynamically but until I get the new pcb here I won't be able to experience anything. However, if the back slot were just a duplicate of slot 2, none of these ideas would be feasible.

Hi Kdl,

Each slot has it's own slot select signal attached to a different fpga pin, so any sub-slot could be redirected to any of the slots (or any non expanded slot).

Van erpirao

Paragon (1315)

25-06-2019, 21:29

and if slot "2" and "3" are used, a switch marks if "2" is I / O or complete, leaving "3" in the other option
slot "3" will be very useful for I / O devices such as opl4 or V9990

Van KdL

Paragon (1450)

25-06-2019, 22:47

ducasp wrote:

Hi Kdl,

Each slot has it's own slot select signal attached to a different fpga pin, so any sub-slot could be redirected to any of the slots (or any non expanded slot).

okay, thank you!!

Van ro

Scribe (4963)

26-06-2019, 08:25

time for a news post, perhaps?

Van KdL

Paragon (1450)

26-06-2019, 12:32

ro wrote:

time for a news post, perhaps?

You should ask Victor, I know the final name of this machine may be changed.

Van KdL

Paragon (1450)

26-06-2019, 20:43

I thought about the dynamic code to use for the 3rd external slot.

When slot 0 is expanded:
slot 0-1 is populated internally by MEGASDHC or NEXTOR KERNEL;
slot 3-2 is used as a 3rd external slot.

When slot 0 is not expanded (SETSMART -F9): <-- a rare condition
slot 3-2 is populated internally by MEGASDHC or NEXTOR KERNEL;
the third external slot is deactivated.

Code example:

    iSltErm     <=  mem when( (w_prislt_dec(0) and w_expslt3_dec(1) and (w_page_dec(1) or w_page_dec(2))) = '1' and Slot0Mode = '1'     )else   -- 0-1 (4000-BFFFh)   128 kB  (MEGASDHC.ROM + FILL64KB.ROM) or NEXTOR16.ROM
                    mem when( (w_prislt_dec(3) and w_expslt3_dec(2) and (w_page_dec(1) or w_page_dec(2))) = '1' and Slot0Mode = '0'     )else   -- 3-2 (4000-BFFFh)   128 kB  (MEGASDHC.ROM + FILL64KB.ROM) or NEXTOR16.ROM
                    '0';

However, several tests will be needed first to decide whether this situation is as stable as the one currently adopted, where simply the slot 0-1 turns out to be the 3rd expanded slot.

Van iamweasel2

Paladin (713)

26-06-2019, 20:58

Any ideas of what to do with the extra space in the FPGA of this machine?

Van erpirao

Paragon (1315)

26-06-2019, 21:00

R800 & Music Module..