need help with panasonic fs-a1 and mapper megaram 512

By mimo77

Supporter (4)

mimo77's picture

09-10-2021, 20:34

help, kind people. I got FS-A1 and mapper megarom 512 2SD cartridge. 1.5 years ago, my little daughter pressed something, or I did something wrong. I have been unable to play my MSX for over a year now, trying to solve my problem but not successfully oO

MSX with inserted megarom cartridge is loaded into disk BASIC 1.0 . there is a screen for loading the cartridge, he sees the memory card.
through the FDISK call I can format the map and create partitions. but for some reason the FAT16 section does not work, disk BASIC 1.0 is loaded, but the DRVINFO call does not work, and I do not see the files.
FAT 12 works, DRVINFO call sees one partition, drive A SDMapper Driver v1.04 slot 1-1, lun 1
the FILES call shows files on the memory card, but does not see the directory
on my memory card:
AUTOEXEC.BAT
(
PATH A:\DOS\ A:\SR
CD GAMES\
SR /S
)
NEXTOR.SYS
COMMAND2.COM
dir:SR
dirBig smileOS
dir:GAMES

sorry for my english, i use google transliteration

Login or register to post comments

By st1mpy

Paladin (838)

st1mpy's picture

09-10-2021, 21:27

Have you tried putting the cartridge in mapper mode (not mega ram mode) I guess it has some switches on the top of the cartridge.

By mimo77

Supporter (4)

mimo77's picture

09-10-2021, 21:47

there are two switches on the cartridge. for any combination of switches, the result is the same: disk basic 1.0 ...
if you put the DOS-OS and DOS.sys files in the root of the memory card, then this DOS is loaded, and instead of disc basic I have a DOS., but I also cannot use the files ...
sorry i don't understand much about MSX, only used it for games

By st1mpy

Paladin (838)

st1mpy's picture

10-10-2021, 14:32

(BTW I don't own one of these cartridges, so others with experience can confirm the following).

The 2 switches, one on the left is on/off for using the memory on the cart (can be used as a mapper, or megaram). For new msx users, a mapper is like adding ram to msx to have more memory, and a megaram is a way of simulating a megarom cartridge. A megarom cartridge is a commercial rom cartridge that contains a game program larger than 1 mega bits (128 kilo bytes). You would want this to be on, when off, this cartridge will act as just a sd reader (that's like adding a hard disk to msx). But for 64kb machine like yours (assuming it hasn't been modified), this means your machine will only be able to run dos1 without the extra memory. Which means no directories(folders) and so your autoexec wouldn't run sofarun (and I think it needs dos2?).

The switch on the right is to set to use either the mapper or megaram. The limitation of this is that for 64kb machines, you can't have dos2 and megaram at the same time (you need to modify the machine to have 128kb or more or add another mapper cartridge).

If you set the switch to megaram, you would be in dos1 (as you have a 64kb machine) so you should have the execrom (the tool to use megaram) in the root folder. See if you can run a megarom game. Makesure you have the COMMAND.COM and MSXDOS.SYS files in root.

If you set the switch to mapper, add the nextor files in root. Your autoexec should run the sofarun, assuming all those folders and contents listed in the autoexec exist.

You should change the switch position when the power is off and the start the machine, it's not effective to change it while it's on unless you reboot.

By Grauw

Ascended (10158)

Grauw's picture

11-10-2021, 12:06

This is a recurring question and the lack of Nextor DOS2 support in MegaRAM mode on machines with less than 128K internal RAM is the reason why I always recommend the MFRSCC+SD 512K or Carnivore2 over the SD-512, since those two have a separate mapper RAM bank instead of a shared one.

But you can still use the MegaRAM in DOS1 mode as st1mpy described, one additional requirement to use the cartridge in DOS1 mode though is that the partition must be FAT12.

When using the cartridge in DOS2 with the RAM set to RAM mapper mode, some games will also be able to load using SofaRun, but compatibility is less than via MegaRAM.

By mimo77

Supporter (4)

mimo77's picture

11-10-2021, 12:10

thank you, you helped me progress in solving my problem.
I am glad and can now use my msx.

thanks for the hints, I was able to run msxdos 1.8 and execrom loaded the game, but only the simplest one at 16kb. anything that no longer worked, any position of the switches on the cartridge did not help. I disassembled the cartridge, carefully examined the board. on the 512kb microcircuit one contact came off. I have no idea how this could have happened. I soldered it and it worked. dos2 and nextor started to run, now I can load msx2 games of 130kb. 128kb apparently the limit of the memory size for my fs-a1.sd card with fat16 has not yet been launched, and sofaran has not yet been loaded using autoexec. maybe you need to check the memory on the cartridge

By mimo77

Supporter (4)

mimo77's picture

11-10-2021, 12:25

the problem with setting up this cartridge has been discussed here many times. I read these forum topics, I carefully did everything as written, studied the instructions, and advice from the forum. nothing helped. but it turned out that my cartridge is half broken.