Tape loading - blocks with checksum
These were sometimes used for 128K games and had a searching / loading message, ie. Loading Block 08, then if a block didn't load right one could rewind a bit and it would search till it found it and try to reload. There was a slight overhead in terms of the time it took to load, but it was much easier to retry a segment. Anyone know if there is a utility in the archive for saving/loading in this way?
Post edited by dmsmith on
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Yes, there is. Blok Load by Theo Develegas does this. His other tape utilities are also worth a look.
I remember back in the mid 80's I wrote a rudimentary "block loader" for transmission over CB radio to friends (Naughty eh?)
It was great, because we could transmit (in 1K) blocks so, after the first transmission the recipient may say "I didn't get 5, 9 & 8" so I would just send the relevant blocks again to complete their transfer.
As long as they got the first (basic with embedded m/c) block, the rest would/should load automatically, and indicate any badly loaded 1k blocks.
It was slow, but it worked a treat.
The toughest part was the mod to the CB Mic input, but it wasn't rocket science.
I guess you had to be there, but it really worked and over some good distances at quiet times, when there was little interference from other CB users.
That is pretty cool, I bet you annoyed the hell out of the other users though. Like the people who insisted on playing music through it all the time. :)
How long did a typical game take to send?
Been there, done that ;)
Inspired by my local radio station (GWR) at the time running "Radio Software". After closedown they would transmit programs over the air, you just tuned in and recorded them to tape. alarm clock programs seemed to be the most popular if I remember correctly!
Tis not that dissimilar to how a BBC / Electron loads data (minus the noise) in small blocks.
I think there was a Dinamic loader (Dinaload?) which did something similar and didn't have the long leaders.
there was a local pirate radio station here that did that also , but I think they were transmitting commercial games.
Yes, spanish release of Astro Marine Corps used that kind of loader. It had very short pilot tones (I'm unable to hear them), so it didn't took too much longer to load. Even it allowed you to play master mind while loading!
An' you know what they said?
Well, some of it was true!
It's not as forgiving as Bleepload - pause then rewind the tape for some reset fun... ;)
We had one here too, I remember I got Jetset Willy 32 from it, and I'm sure I still have it.
Bubble Bobble is a game that had that bleepload thing, it took ages to load, but it was good that if you had an error you could rewind.
Never tried transmitting over CB, but makes me wish I had tried something like that with the Binatone walky-talkies I got one christmas. - "come in Ray!" That might have been the start of a slippery slope for me though.
Block.s contains two routine to save and load memory in block of up to 256 bytes. If an unrecognised block is found, it just loops back to continue waiting. You could add a "Rewind tape" prompt at that point.
If you have a modified ROM that lets you run machine code as commands, the LOAD.s and SAVE.s are source for LOAD and SAVE commands to load and save memory as blocked files, eg with the JGHROM I could do *SAVE screen 4000+1B00 to save the screen as 27 256-byte blocks, and load it back in with *LOAD screen 4000.
Was about to say the same. 131 byte blocks; presumably 128 bytes of data, 2 bytes for block id and 1 byte checksum.