WIP: VIC-2020 MINIMON cartridge

[ops]

Count me in.

[majikeyric]

Count me in for 2 physical units and a software image for the Ultimem

All the enumerated features sound great, you seem to have optimized MINImom to the MAXimum

L ["<file name>" [<dev.-#>]] - load file into memory

Does it mean you can also load a file at any memory location ? overriding the file load address ?

[Mike]

L ["<file name>" [<dev.-#>]] - load file into memory

Does it mean you can also load a file at any memory location ? overriding the file load address ?

<dev.-#> is the device number. 1 (= tape) is default and you'd use 8 or 9 for floppy (higher device numbers like 10 or 11 must be given in hex).

The L command always loads a file to the same memory location it was saved from. This doesn't pose any problems in practice: 65xx machine code generally isn't relocatable anyway, and if you need a data block at some different place, the T command can be used for this.

Count me in for 2 physical units and a software image for the Ultimem

O.K. for the two units.

If you own the hardware, you can always create a software image for yourself with the S command, but I won't do a software-only release.

[majikeyric]

OK Mike! many thanks!

[Mike]

UPDATE:

The hardware development team is currently finalising the PCB design of the VIC-2020 MINIMON cartridge:



The design features:

• switch SW1 to put either MINIMON in I/Ox or make the cartridge completely pass-through,
• switch SW2 as reset button,
• jumper JP1, *) which allows to put either a 2716 EPROM (or equivalent) or a 6116 2Kx8 SRAM into the ZIF socket, and
• jumper JP2, which allows to (temporarily) disable BLK5 (... draw your own conclusions from this ).

The tabs oriented towards the VIC-20 will be gold plated. The tabs going away fron the VIC will carry a female 44 pins edge connector.

Thus far there are the following pre-orders (except my own and eslapion's):

ops - 1 cartridge,
chysn - 1 cartridge,
majikeyric - 2 cartridges,
tokra - 1 cartridge.

Anyone else in for the first batch?

As I wrote already, eslapion and me will need to negotiate on a price tag and that will at least partly depend on the number of cartridges built.

Greetings,

Michael

P.S. and *): JP1 will be a standard 3 pin jumper block in the finalised version

[chysn]

When a 2Kx8 SRAM is in the ZIF socket, will it be in block 5?

You helped me install a 6116 in my VICMON cartridge at $A000, and it's been super-valuable. That 2K is a scratchpad for quick proofs-of-concept, or a place I can use to develop tests of subroutines in "main" memory, or a way to try multiple approaches and compare them. Sometimes it's just a place where I can refresh my memory as to whether BIT sets or doesn't set the zero flag on a match. I absolutely love it.

I've already ordered a 6116 to have at the ready!

[Mike]

When a 2Kx8 SRAM is in the ZIF socket, will it be in block 5?

Whatever is installed in the ZIF socket, be it the EPROM with the MINIMON firmware or a SRAM, will appear in the I/O area, in $9800..$9FFF.

You helped me install a 6116 in my VICMON cartridge at $A000, and it's been super-valuable. That 2K is a scratchpad for quick proofs-of-concept, or a place I can use to develop tests of subroutines in "main" memory, [...]

You could switch your VIC-1110 +8K RAM expansion to BLK5, put it as slave cart into the MINIMON cartridge, and have a much larger scratchpad available.

I've already ordered a 6116 to have at the ready!

The SRAM chip in the ZIF socket is surely useful when you want to place other, soft-loadable utilities into the I/O area, instead of MINIMON. That could be SJLOAD or the Rabbit tape accelerator. These utilities then likewise run alongside, for example, a +35K RAM expansion as slave cart.

[chysn]

Oh! Gotcha. Yes, it also sounds like I can use Minimon with my hot-rodded Vicmon cartridge (+3k @ $400 and +2k @ $A000) and just use Minimon instead of Vicmon.

I find the reverse disassembly of Vicmon useful, but I’d happily give it up for something that doesn’t savage zero page and turn BASIC into malware.

[Mike]

Yes, it also sounds like I can use Minimon with my hot-rodded Vicmon cartridge (+3k @ $400 and +2k @ $A000) and just use Minimon instead of Vicmon.

That is perfectly possible, yes.

You can also use Super Expander as slave cartridge. Super Expander uses the addresses $02A1..$02FF for workspace, which is one of the reasons MINIMON stays clear of that memory range.

I find the reverse disassembly of Vicmon useful, but I’d happily give it up for something that doesn’t savage zero page and turn BASIC into malware.

It is rather difficult to understand why VICMON clobbers BASIC workspace, indeed.

[Mike]

Small teaser:



...

[Noizer]

Looks great!

[Vic20-Ian]

Very nice.

I would be interested in one unit please.

Would the software version also work with FE3?

Thanks
Ian

[Mike]

Would the software version also work with FE3?

FE3 on its own is not able to run a software image of the MINIMON firmware. The MINIMON firmware resides in $9800..$9FFF, where FE3 puts its own registers to access the FE3 hardware, and the FE3 cartridge cannot overlay that address range with RAM.

It is entirely possible though to operate FE3 as slave with the MINIMON cartridge.

I would be interested in one unit please.

Thank you for your interest. There are still some tests necessary, and when these tests are finished I will contact possible suppliers. As soon as the cartridge is available for purchase, I'll post a link here.

[chysn]

Looks great!

[chysn]

Is the software already burned to chips? If not, I'd implore you not to do this:

MINIMON changes the BRK and NMI vectors, the latter one to keep itself and the BRK vector 'life' even when STOP/RESTORE is pressed.

There's no particularly good reason for the monitor to "rootkit" the normal STOP/RESTORE vector reset like this. I'd assume the custom BRK vector is set when the monitor is started anyway.