The dark arts of tape loading?

Frequently Asked Questions about the Sinclair ZX81
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Macross_VF1
Posts: 2
Joined: Sun Dec 09, 2018 5:05 pm

The dark arts of tape loading?

Post by Macross_VF1 »

Hi, new member here!

I've recently acquired a ZX81 with a Memotech 16k and some tapes, Raiders/Bombers being one of them. Since the RF picture was garbage I immediately modded it to have composite out and it seems to work fine after that.

However, as I'm beginning to understand, loading from tapes can be quite tricky. I have an old school CRT TV that I'm using and I certainly get some reaction on screen when trying to load but nothing really happens after the supposed loading time.

The tape player I'm using is originally taken from one of my Spectrums and it lacks a tone and treble dial, could this be the reason for the tapes failing to load? Also, how do I know the memory pack is is connected and working properly?

Finally, I think I've read somewhere that you can use a standard Smartphone to load games from, but I haven't really found any instructions on how to do so.
Lardo Boffin
Posts: 1275
Joined: Sat Nov 26, 2016 2:42 am

Re: The dark arts of tape loading?

Post by Lardo Boffin »

If the zeddy switches on and you get a K there is a good chance the RAM pack is working.

There are more sophisticated checks but try this:-

DIM A(3000)

It should return 0:0 afterwards.

It is trying to dim an array of 3000 elements which more or less fills the RAM. If you try this without the RAM pack it will return an error number.

Loading is a dark art - the volume has to be perfect and the lack of fine control on yours may be a problem. If you have any 1K games try those first without the RAM pack attached. At least you only have to wait 20 to 30 seconds before you know it failed.

Also check the toggle switches on the back of the RAM pack. If it is not set correctly it won’t work (I found this out the hard way). On mine 1 is down, 2 and 3 are up, 4 is down.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
Iss 3 ZXVid
TS 1000 iss 3, ZXPand AY, ZX8-CCB, ZX-KDLX & ChromaSCART
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Spectrum +2a
Macross_VF1
Posts: 2
Joined: Sun Dec 09, 2018 5:05 pm

Re: The dark arts of tape loading?

Post by Macross_VF1 »

Unfortunately I don't have any 1K games. The RAM on the other hand I've already found a manual about so the dip switches are indeed in the correct position.
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mrtinb
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Re: The dark arts of tape loading?

Post by mrtinb »

Many have good experience connecting the output of a PC soundcard to the ZX81. The program file have to be converted from .p to .wav first.

You can also playback the program file from the emulator EightyOne without conversion to .wav.
Martin
ZX81, Lambda 8300, Commodore 64, Mac G4 Cube
Clive Alive79
Posts: 2
Joined: Thu Apr 04, 2019 11:50 pm

Re: The dark arts of tape loading?

Post by Clive Alive79 »

We never really had that problem with the ZX81, because we wrote short programs and used a Winky.

However, we did have problems with large programs on our TRS80. One program took 20 minutes to load and it was hit or miss until I realized that if the refrigerator kicked on at any point during the load, it wouldn't work.

That's how sensitive it can be. Once I unplugged the fridge during the load, it worked flawlessly. The trick after that was remembering to plug it back in!!
Lardo Boffin
Posts: 1275
Joined: Sat Nov 26, 2016 2:42 am

Re: The dark arts of tape loading?

Post by Lardo Boffin »

On some of my zeddies typing LOAD”” ENTER and then pressing play is often enough to cause a failed load. I assume it makes some unwanted noise when starting up which confuses it.
Always press play and then press ENTER. :D
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
Iss 3 ZXVid
TS 1000 iss 3, ZXPand AY, ZX8-CCB, ZX-KDLX & ChromaSCART
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Spectrum +2a
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