Possible to hear a C64 program load?

Pitch your ideas and suggestions for Retro Gamer Magazine here.

Moderators: mknott, NickThorpe, Darran@Retro Gamer, MMohammed, lcarlson

Post Reply
User avatar
soopytwist
Posts: 113
Joined: Sun Feb 15, 2009 10:48 am
Location: Leicester

Possible to hear a C64 program load?

Post by soopytwist » Mon Mar 12, 2012 10:16 am

I'm having difficulty loading some of my own programs. Not being be able to hear the signal on the cassette and no on screen loading indication is making it difficult to determine when the program starts and when it finishes. Not having an inlay with counter numbers on and finding the right programs and loading them is causing me something of a headache. The sloppy work around is playing the tape in a stereo with a tape deck to cue-up the program and then try, but again there's no telling when the program ends and no way to record the counter number for each program.

The great thing about my 48k ZX Spectrum was the ability to actually hear the binary code of the program as it loaded into memory. The Commodore 64 never did that, which I found annoying in the early days - the only indication that anything at all was loading was what was going on on the screen; but not all programs do that.

So, in a roundabout way, I'm asking if there is a BASIC listing that can be run prior to loading a program that allows me to hear what's on the tape though the RF lead?
Or is it possible to connect headphones to some of the wires in the datasette lead? If so which ones? And if I did that would it affect the strength of the signal to the C64?

User avatar
necronom
Posts: 5648
Joined: Thu Dec 01, 2005 5:23 pm
Location: Middlesbrough

Re: Possible to hear a C64 program load?

Post by necronom » Mon Mar 12, 2012 4:15 pm

Couldn't you time it on a normal stereo with your watch, then when you play it on the C64 start your timer and you'll know when it's got to the end. I expect all tape players play at the same speed (give or take 1%).
Image
The Retro Gaming League _ -= My YouTube Videos =-
The eighties aren't over. I'll say when the eighties are over. The eighties are never over! You don't just turn off the eighties! - Jack Howitzer, GTA V

User avatar
TMR
Posts: 5756
Joined: Wed Dec 21, 2005 10:56 am
Location: Leeds, U.K.
Contact:

Re: Possible to hear a C64 program load?

Post by TMR » Mon Mar 12, 2012 4:33 pm

necronom wrote:Couldn't you time it on a normal stereo with your watch, then when you play it on the C64 start your timer and you'll know when it's got to the end. I expect all tape players play at the same speed (give or take 1%).
That's probably the best bet i'd have thought, it's possible to wire speakers into a tape deck i think but i've never seen it actually done and there's no way to route the sound to output to the telly in software unless the loader is written specifically to do that (there are a few that do, but it wasn't popular).

User avatar
miner2049er
Posts: 415
Joined: Thu Dec 08, 2005 3:52 am
Location: Leigh, (Lancashire) UK
Contact:

Re: Possible to hear a C64 program load?

Post by miner2049er » Mon Mar 12, 2012 4:48 pm

A mate at school had a speaker rigged up to his cassette deck, a result of having a C90 full of games. Not sure which wires you need but it can't be hard to get a schematic and find out.
http://www.jamesonline.net
Now I just need an amusing tag line.

User avatar
Mire Mare
Posts: 2560
Joined: Sun Mar 01, 2009 7:11 am
Location: onboard the Stellar Patrol Ship Feinstein

Re: Possible to hear a C64 program load?

Post by Mire Mare » Mon Mar 12, 2012 7:14 pm

I used to have a Mills 'Load-it' dattassette. It had adjustable tape head and an led display which made loading from tape a bit easier. Mine was very reliable and was used regularly for years until it died. Probably difficult to get one nowadays though :(

User avatar
soopytwist
Posts: 113
Joined: Sun Feb 15, 2009 10:48 am
Location: Leicester

Re: Possible to hear a C64 program load?

Post by soopytwist » Tue Mar 13, 2012 10:21 am

Mire Mare wrote:I used to have a Mills 'Load-it' dattassette. It had adjustable tape head and an led display which made loading from tape a bit easier. Mine was very reliable and was used regularly for years until it died. Probably difficult to get one nowadays though :(
Funny you should say that, I do actually have a Load-It datasette, but rather strangely the LED's don't seem to indicate when the program starts and when it finishes; the LED's stop before the program has finished.

Actually it's a self mod Load-It datasette. I have a thread on here about whether or not my C64 is broken. It turned out to be the two datasettes I had, one the basic model and the other a Mills Load-It. I salvaged the Load-It PCB from the Mills one and soldered it to a new original 1530 C2N unit I bought from eBay. Other tapes work fine but my C90 cassette doesn't seem to load anything at all and those LED's don't appear to indicate correctly the start and ends of the programs which is most odd. My modified datasette clearly works though as it loads games fine and adjusting the azimuth does indeed alter the LED's and it will load even the most stubborn games, like The Goonies which always failed to load before I had a Load-It datasette.

Perhaps the cassette is borked? I cloned the tape to another and tried that, still doesn't work. Maybe the programs were never written to the tape correctly in the first place? Just a Shift+Run/Stop and pressing play won't find any programs on the tape, where you'd normally get "found whatever" and pressing the Commodore button to "load" it.

I managed to find a schematic of the datasette lead. The White wire is "Read" so one would assume this carries the audio signal to the C64. Should be fairly simple to attach a wire to this and plug it into the C64 at the same time. I'll have to give that a go. I also found a simple circuit to build an MP3 to C64 converter, fooling the C64 into thinking its loading from the datasette (you have to manually send signals to the C64 from the PC to start and stop the tape - the "sense" wire in the datasette lead).

The other alternative are the suggestions from my previous thread but I was hoping for a simpler solution. So a POKE listing to hear the signal down the RF lead isn't possible then?

Stainy
Posts: 195
Joined: Tue May 22, 2007 3:41 am

Re: Possible to hear a C64 program load?

Post by Stainy » Wed Mar 14, 2012 5:45 am

Mire Mare wrote:I used to have a Mills 'Load-it' dattassette. It had adjustable tape head and an led display which made loading from tape a bit easier. Mine was very reliable and was used regularly for years until it died. Probably difficult to get one nowadays though :(
Me too :)

First one had a speaker.. Ten I had one with the LED lights..

User avatar
Mire Mare
Posts: 2560
Joined: Sun Mar 01, 2009 7:11 am
Location: onboard the Stellar Patrol Ship Feinstein

Re: Possible to hear a C64 program load?

Post by Mire Mare » Wed Mar 14, 2012 6:54 am

Stainy wrote:
Mire Mare wrote:I used to have a Mills 'Load-it' dattassette. It had adjustable tape head and an led display which made loading from tape a bit easier. Mine was very reliable and was used regularly for years until it died. Probably difficult to get one nowadays though :(
Me too :)

First one had a speaker.. Ten I had one with the LED lights..
Yes! I thought mine had a speaker, but I wasn't 100% certain so didn't add that into my post. I did think it had a volume control, or a switch, to allow you to hear the software loading. Ingenious stuff ;)

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest