Vic 20 disk games original releases?

[TheDash]

I'm just wondering if any Vic 20 games were originally released on disk? I've never seen any, although the 1541 disk drive was certainly available for the Vic 20 pretty much from day 1, so long before the C64 was launched and which certainly did have original disk game releases.

 

Does anyone know of any Vic 20 games originally released on disk?

[carlsson]

I believe the general consensus is that almost no software for the 1540 was released commercially. Denial WIKI has four productivity titles listed. I have a vague memory of some kind of Oil Barons type game released for the VIC-20 +16K on disk but I don't know much about it. Probably the fact that the disk drive cost 50-100% more than the computer meant the number of units sold were quite few.

[Mayhem]

Yes, but not very many. I own one Vic20 game on disk from the 80s (by ALA Software) and I've seen at least one other published by them on disk too.

[+SpiceWare]

On 11/27/2022 at 6:23 AM, carlsson said:

Probably the fact that the disk drive cost 50-100% more than the computer meant the number of units sold were quite few.

 

There's also the RAM issue - game cartridges were 4K, 8K, and 16K in size, which wouldn't fit in the VIC's 3.5K of available RAM.  So disk games would also require RAM expansion, which would further reduced the number of people who could buy them.

[carlsson]

Not necessarily. The 1540 uses 0 bytes of computer RAM once plugged in. You can fill a floppy disk with 40+ games for unexpanded VIC-20 and load them one by one, or have a game that loads multiple parts, just like some tapes did. The game cartridges of course are ROM based and mapped into a different area than the RAM.

[+SpiceWare]

Yeah, I understand that using the drive doesn't use up any RAM.

 

Games tend to use redefine-able characters, which would eat up a chunk of the 3.5K RAM. There's a mode lets you redefine just half the characters, which uses 1K of RAM vs 2K needed to redefine all 256. I used that mode when I was writing games on my VIC, but remember it being a big constraint before I could afford to buy a 3K RAM expansion. 

 

Multi-load would help, but would still limit what a game without RAM expansion could do compared to a cartridge game with up to 16K of ROM.

 

 

 

[carlsson]

Actually you often can get away with only 64 UDG's which uses 512 bytes. I've programmed quite a bit on the VIC-20 too, so I know its limitations. Of course tape based games also redefined graphics, and also need to use part of the cassette buffer for temporary data, which the floppy drive doesn't need so it actually has a little bit more RAM in the lower 1K to use for temporary storage, machine code routines etc.

 

Here is a price list from October 1981 which is reasonably early on given it was launched in March 1981. Some highlights:

 

VIC-20 computer: $299.95
1540 floppy drive: $599.00 (available from December 1981)

1530 tape recorder: $75.00

3K RAM expansion: $39.95

8K RAM expansion: $59.95 (seems like this one was just released, and no 16K expansion yet)

Utility cartridges: $59.95 - $69.95

Game cartridges: $29.95
 

Of course prices dropped quite a lot in the following two years, but as the C64 gained ground from the beginning of 1983 and Commodore experimented with other models such as the UltiMAX (which only launched briefly in Japan) and eventually planned the TED series, I kind of understand if 3rd party software publishers didn't put much effort into making floppy disk games for the VIC-20, with or without memory expansion, as the floppy drive still would be a quite expensive peripheral and those who could afford it, might as well upgrade to one of the newer computers.

[TheDash]

On 11/28/2022 at 1:40 PM, Mayhem said:

Yes, but not very many. I own one Vic20 game on disk from the 80s (by ALA Software) and I've seen at least one other published by them on disk too.

What is the title of this game, and also what type of packaging is it in?

[Mayhem]

17 hours ago, TheDash said:

What is the title of this game, and also what type of packaging is it in?

http://sleepingelephant.com/ipw-web/bulletin/bb/viewtopic.php?t=2758

[carlsson]

Ok, so that one anyway requires a 8K RAM expansion, but then again quite a few VIC-20 owners had at least 8K or 16K expansion eventually. And if you had $400-$600 to invest in a floppy drive, you probably had another $50 to invest in a memory expansion too.

 

It makes me wonder if the unexpanded VIC-20 is the computer with least amount of RAM for which you can actually attach a floppy drive. I believe the Atari computers sold with 8K and upwards, at least after a while. Not sure about the CoCo range. European low-end systems like ZX-81 doesn't even support microdrives IIRC. While it isn't a particularly exciting record to set, someone got to do it. Perhaps there was some higher end S-100 bus systems with floppy drives but very little RAM onboard.

[Mr SQL]

19 hours ago, carlsson said:

Ok, so that one anyway requires a 8K RAM expansion, but then again quite a few VIC-20 owners had at least 8K or 16K expansion eventually. And if you had $400-$600 to invest in a floppy drive, you probably had another $50 to invest in a memory expansion too.

 

It makes me wonder if the unexpanded VIC-20 is the computer with least amount of RAM for which you can actually attach a floppy drive. I believe the Atari computers sold with 8K and upwards, at least after a while. Not sure about the CoCo range. European low-end systems like ZX-81 doesn't even support microdrives IIRC. While it isn't a particularly exciting record to set, someone got to do it. Perhaps there was some higher end S-100 bus systems with floppy drives but very little RAM onboard.

That's interesting the VIC-20 actually gains memory after you add a disc drive, that's a compelling reason not to upgrade the 5K RAM.

 

Most users had tape drives but if it were the other way around I bet we would have seen software take advantage of that extra memory.

 

The CoCo required you to upgrade because DOS used 2K of the memory so not all programs could run that previously did.

[carlsson]

To be honest there are not copious amounts of memory you can use for other purposes:

 

Cassette buffer, address 828 - 1019 (192 bytes) which I think you can utilize more or less fully with disk operation. Sure you can fill it with tape operation too but any time you load from cassette it will get overwritten.

 

I think there are 21 bytes in zero page which mostly refer to tapes too, but it is brave to start to reuse single bytes in zero page for own purposes. There is an error log at address 256-318 (63 bytes) which co-exists with the stack pointer, so you wouldn't gain more memory, only be able to get deeper into the stack before tape routines mess up your stack pointer. There are another 2 bytes that hold the IRQ address while loading from tape.

 

At the same time, there doesn't seem to exist any specific addresses used for floppy drive, at least not in the low RAM.

 

There already is a block of 95 bytes in the low 1K, between 673 and 767 which is unused. Combined with the tape buffer (though not continuous memory), that is up to 287 bytes you could use for short machine code routines, storage of data etc that doesn't eat anything from the 4K RAM you normally have to share between BASIC and the screen matrix.

[Harry Potter]

Carlsson, you're right about the extra space.  If anybody here uses cc65 to program the Vic20, I have some alternate configs to make use of portions of the first 1k of a Vic20's memory for code and data.  I call this technique the Cubbyhole technique.  I also have configurations for 8k and 16k cartridges.  For smaller programs, I have CBMSimpleIO, which is a replacement for printf() and scanf() that produces much smaller code.  You can find the configurations at c65 additions - Manage /memory cfgs at SourceForge.net and CBMSimpleIO at c65 additions - Manage /ui at SourceForge.net.  I also have versions of MadLib at c65 additions - Manage /game at SourceForge.net.  The Vic20 version requires 8k memory expansion.  Une more thing: I have the Vic20 version of DirMenu at the same location as CBMSimpleIO.  DirMenu is a menu program that allows you to run any program on a disk.  All non-1581 versions are worth <1k in size.  I ask you to try these out and tell me what you think.