HyperDriver

BillC suggested a value of around 5 Ohms. This will draw 1 Amp from the supply & test it out under load. A 10 Ohm resistor would draw 500mA. At 1 Amp the resistors would need to dissipate 5 Watts. So to do this you would need to make sure the resistors are up to the job. You can always put the resistors in parallel to make up the load. A couple of 10 Ohm 2.5W resistors in parallel would give you a 5 Ohm 5W load. With regard to the input voltage to the regulator fluctuating, perhaps check the ac voltage from the secondary side of the transformer to see if that is fluctuating as well.

This doesn't look right either. Bit concerned that the input side drops to 7.8v for no apparent reason.

Hmm. As BillC says, a 10 Ohm resistor should give you another 0.5v on top of the nominal output voltage of the regulator. Are you sure it wasn't a 1 Ohm resistor? You can check the nominal output of the regulator by grounding the centre pin. You should see 5v +/- 0.2v with the standard regulator, or +/- 0.1v with the "A" suffix type. I would replace C104 (10,000uF) as well. Don't know what kind of condition it's in after all these years.

@enito Any of the caps linked to by you & Spancho will be OK. (Although make sure you pick the 104k type in your last link). Also, of course, make sure that the body of the cap fits the space of the existing solder pads.

Those decoupling capacitors are 0.1uF (100nF), not 0.01uF. u1 is the same shorthand as 0u1 which represents 0.1uF. If you look at the hardware manual for the 65XE the board photo shows those caps marked as 104 which is shorthand for 10 followed by 4 zeroes (in picofarads) = 100000pf = 100nF. Looks like your board has glass caps fitted. Can you see if any of those caps above the memory chips have 104 on them?

When you say 0Ω, do you actually mean zero Ohms (short circuit) or infinity Ohms (open circuit)?

I have ordered the hardware. I've been trying to find out what is missing/crippled in the trial version of Atarimax ProSystem software, but can't find any details.

Right. So I need a hardware interface first. I've seen a place in UK selling Lotharek's 10502PC Sio2PC USB REV2. I take it that the AspeQt, or RespeQt software allows reading from pc to Atari and reading from 1050 drive to pc? https://retrolemon.co.uk/8-bit-mass-storage-devices/57-10502pc-sio2pc-usb-rev2.html I also looked at the interface on Atarimax, but that is shipped from USA, & the software for it is another $50.

That's OK. No problem. I've been in a similar position myself (I think most of us have at some point unfortunately). We gathered addresses from Atari magazines & sent off our mail shots to them. We never had any adverts in any magazines. It actually didn't work out too bad. I was quite surprised at how many orders we received back using this method. I did try handing out our flyers at a computer show once, but was stopped by a security guy. I had only handed out around a dozen or so. He asked which stand I was from & whether I had permission. Erm...that put a stop to that!

HF Developments had no connection with Chaos! computers. When demand for the drives slowed down, one of our customers bought up our remaining stock. He used the name Chaos! computers & advertised in an Atari magazine (as shown in a previous post).

@Nezgar We didn't make any changes to the Lazer ROM. It was copied exacly as it was on our "gang of 8" EPROM copier. We didn't see any need to change anything. All I did was change the wording in the software to our brand. As far as I could tell, it did everything we needed it to do, so left it as it was. Of course we couldn't check out every possible function. Having now found some screen shots of the menus, it looks like ver.1 of our software only had 3 options, while ver.2 may have had 9. I say may, because I'm now wondering if we modified the Happy software for our ver.2, rather than modify any Lazer ver.2 software? Did Lazer even bring out their own ver.2 software anyway? Perhaps the options that I mentioned that I disabled in my earlier post were the ones that were incompatible between the Happy software & our boards? Hmmm... I'm getting more & more anxious to get the loft ladder out now! ? I hope my disks are still working after being stored for so long. I will try & make an image/dump of the disk & EPROM as soon as I can work out what I need & how to do it (and as soon as I find the time).

@E474 I don't recognise that Lazer/US Doubler configuration. The only Lazer upgrade I saw was the plug in board that we copied. Does anyone have an actual Lazer board? I ask because I can't remember if it had the RAM & EPROM side by side. Our boards had the RAM piggy backed on to the EPROM. I can't remember if that was our idea, or if the Lazer was also like that. I will try to dig out my stuff in the loft as soon as I can. To be honest, I don't know when that will be. Hopefully it will be before I retire in 2 and a half years time. ? Wish I had more time on my hands, as I'm getting quite intersted in this again now. It's interesting to hear about what you can do now, with interfacing the Atari stuff with the pc. It will be a learning curve for me, as I've completely lost touch with my Atari's for decades now. I've noticed .atr files on many posts here. I take it these are software dumps? As for having fun back then, well definitely yes! Things seemed so much more exciting & enjoyable in those days. Loads of magazines to buy, loads of computer shows to visit. Great times. Things seem so much more bland in these pc times.?

Wow. I can't believe that the Hyper Drive is still getting talked about after all these years! I'm the "F" half of "HF Developments". Me & Mr. H were the original rip-off merchants of the Lazer Drive, which was a rip-off of the Happy Drive. I still have all my Atari stuff up in my loft somewhere, which should include all the Hyper Drive stuff. When (if) I get time, I'll hunt around for it. It's quite nostalgic to see members on here discussing somerthing that me & my mate used to sell around 30 (?) years ago! My recollection about some of the details may be a bit hazy after all these years though.? I was an avid collector of all thing related to Atari 400/800, so snapped up the Lazer drive as soon as I saw it advertised (could't afford an original Happy). As we were working for a large electronics company, we had access to EPROM erasers & copiers, & decided that we could easily duplicate the Laser & sell it under our own brand. Luckily, there was an electronics component shop right opposite our workplace who could supply some of the components (eprom, memory & logic chip), & the 6502 was from Cricklewood Electronics (or it may have been the other way round). There was also a stationary shop nearby who could supply the jiffy bags at a good price. Mr. H found a place to etch & drill the boards. So that was the hardware sorted, now for the software. It was all very low tech! With the 1050 opened up, I would look to see where I needed to "rebrand" the software by simply looking to see where the disk drive head was. I would then use a hex editor to look for the wording that needed changing in that area. I also changed the colour of the menus I think to a more readable blue background. From my hazy memory, I think that there were also some options on the original Lazer software that didn't actually work, so they were removed. I wish my memory was better, as I can't remember what options were added to ver. 2, or where it came from. I can only assume that Lazer brought out enhanced software & I went through the same procedure to rebrand that as well. Or did the Happy software work with the Lazer board? Again, I may be mis-remembering, but I thought the Happy software was incompatible with the Lazer hardware. Can anyone confirm this? I made up a ribbon cable from the socket that the Hyper connected to, & had it dangling out of the case of the drive with another socket on the end, so that I could test each board. I didn't want to keep plugging the boards into the actual socket on the circuit board as it would eventually have damaged it.