Wednesday, September 23, 2015

ADTPro and the Merlin assembler

As I mentioned in my last post, I got a nice Apple IIc off of eBay a few days ago.  So far I'm quite pleased with it, but it hasn't actually been that much fun or useful.  The previous owner (who apparently took very nice care of it) was a user, not a developer.  He bought it new and used it to run his business for many years, and then when it was no good for that it became a game machine for his kids and grandkids.

Unfortunately I'm not really much of an arcade gamer, and in any case the bundle didn't include a joystick (he told me that it didn't work any longer).  And the only other software that came with the machine were applications: AppleWorks, Quicken, and a set of utility programs.  But no development tools or anything that I would be interested in.

So of course I looked into ADTPro.  I just didn't have the cables to hook it up however, and I didn't have the parts to build a DIN connector.  I could have cut the modem cable, and I do have the parts for a DB-9 connector, so I could have made a cable.  But I actually have some hope of eventually using the modem to connect to one of the few remaining dail-up BBS's around, so I didn't want to ruin the cable.

In any case, I ordered the cable from RetroFloppy.  Incidentally, although I didn't talk to any of the guys there, I would recommend them if you need anything.  When I ordered the cable through PayPal, it charged me a pretty hefty shipping charge of around $10.  Well, I didn't think too much about it, but the next day I got an email from one of the guys there who informed me that PayPal had estimated too much for shipping and they gave me a nearly $4 refund.  Honestly, the money isn't that big of a deal, but still it's always nice when a company is honest.

So the cable arrived today and of course I hooked it up as soon as I could.  And it worked without a problem.  I already had a USB-serial converter, so I plugged that into my iMac and ran the ADTPro cable to my Apple IIc.  I launched the ADTPro server and followed the instructions and soon enough I had an ADTPro client bootable disk.  I then created a ProDOS v1.9 System Utilities disk (the Apple IIc came with a much older copy of ProDOS), and two floppies for Merlin-8 v2.58.  It was all simple and worked flawlessly.

So now with Merlin-8 transferred (an Apple II assembler, if you're unaware) I can start doing some development.  I've had the Merlin-8 disk images for a while, and I actually also own a copy of the Virtual-][ emulator (a very nice emulator, btw - highly recommended for a nice, retro feel).  I've got a copy of Roger Wagner's Assembly Lines, so now I plan to start working through that.  Of course, I could have already been doing so using the emulator, but for some reason I really didn't want to until I had a real computer I could use.  But with my Apple IIc and Merlin-8 assembler in hand, I hope to start working through the book.

Stay tuned...

Saturday, September 19, 2015

My latest retro acquisition

As a quick note to those who may have only read my PDP-8 Challenge blog, this blog is my general blog on whatever topic I want to write about - mostly things related to vintage computers.  I haven't updated this in a while because I've really been focused on the PDP-8, but that will probably be changing for a little bit now.

So I'm happy to introduce my latest retro acquisition, a very nice Apple IIc.  I got if off eBay for a pretty decent price, and as a bonus the seller lived in my city so I was able to pick it up the day after I won the auction.  The machine itself works flawlessly, except for a sticky keyboard (more on that below), or at least I haven't found a problem yet.  The bundle came with a bunch of floppies, including 10 blanks, two power supplies, a carrying case, a 1200-baud modem, cables, and manuals.  The previous owner wasn't a developer, so it just included application software - AppleWorks 3.0 & 2.0, Quicken, and other miscellaneous programs and utilities.  A MultiRam C card had also been added, expanding the memory to a total of 256k.  Overall, a good bundle and the guy had clearly kept things in good shape and organized.  This was really good for me, because I have no real experience with the Apple II platform, so finding a good collection like this is a good starting point.

So even before I took possession of my new machine, I ordered enhancements.  I got a 256k upgrade for the MultiRam C card, an Apple mouse, and an external drive.  The drive in particular I was quite interested in, because I have this fear of floppy drives failing.  They're just so loud and of course have many ways to fail, so every time I use one I'm just paranoid it will be the last time.  It's odd because back in the day I never really thought about it, but now of course the drives are much older - and, to be frank, I'm just not used to something making that much noise.  Today, noises like that coming from a computer would pretty much mean we'd be buying a new hard drive at a minimum.  That's why I have purchased SD card readers for every retro platform that I've worked with, and the Apple IIc is no exception.  Unfortunately I'm going to have to wait until October or maybe November before it gets here.  So in the meantime I figured I'd use an external drive so that, if a floppy drive had to fail, the external drive would be a lot easier to replace than an internal drive.  Unfortunately I didn't realize until I got the external drive that I can't really boot off of it, so I can't get around using the internal drive.  But hopefully the external drive will at least allow me to minimize how much I use the internal drive.  And having a second drive is just so much more convenient anyway.

One of the other upgrades I got was an extra 256k for the machine.  I wish I could say I honestly needed that much ram, and maybe I will find a good use for it, but certainly at the moment the 256k that the machine already came with would be more than adequate.  But it was cheap, so I figured why the hell not.  So once I got that, I went ahead and installed it - and resolved my keyboard issue at the same time.  

As I mentioned the keyboard was the only problem with the machine.  It worked, but it was very sticky, making any kind of quick typing impossible.  I did some googling and found that I wasn't the only one who had such a problem, and thankfully I found some answers.  And in the process I also discovered that this was an original version of the Apple IIc, so most of the solutions didn't actually apply to me.  When I started to pop off the key caps, I found a black rubber membrane underneath, and under that a burgandy metallic sheet (see the picture).  Apparently the early version of the IIc had those as a guard against liquids splashing between the keys and damaging the electronics underneath.  But this also apparently caused problems with keys sticking, so it was removed in later models.  So I felt reasonably confident in removing it, but that didn't actually solve my problems.

As I hope you can see from the photo to the right, each of the keys has a little metallic clip.  I have no idea what this is for, but once I removed them from all the keys, they worked fine.  It took me about 30 mins to remove all the clips, but it was well worth the effort since now the keyboard works great.

With the keyboard issues fixed, I then went on to adding the ram.  Following the instructions from the MultiRam C  manual, I opened up the IIc and, lifting the keyboard, exposed the main board.  The picture below shows the main board with the MultiRam C board removed.  It's a bit hard to see, but the bottom two large slots are actually where the CPU and MMU chips go.  But the CPU and MMU fit on the MultiRam C and the card plugs into those two sockets.  You can hopefully see this in the photo of the MutliRam C card itself.  On the MultiRam C card, it had only one row of the ram chips (the smaller chips on the left side).  I added the second row, put the card back in the machine, and that was it.  I then ran the MultiRam diagnostics and, sure enough, I now have 512k.  Additionally when running AppleWorks it reports 365k free, which is of course more than the machine had originally, so clearly it sees the new ram as well.  It's cool to have 512k ram in a retro computer.  Now I just have to figure out what to do with all that memory.

By the way, just to demonstrate that retro computing isn't just for old guys, here are my twin 4-year old girls playing on the my new Apple.  They like to use AppleWorks to type out their names and ABC's.  They even now know how to load floppies, though I haven't yet been able to get them to remember to NOT TOUCH THE EXPOSED PART OF THE DISK!  I swear I nearly have a heart attack whenever they do that - and trust me, with my blood pressure, that's not a minor concern!

If you're curious, that's Trinity in the top picture and Harmony in bottom one.  And that's a Commodore 64 in the background, and the back of a Commodore 1571 disk drive under the monitor.