Yep!

@@PCRetroTech I would so like to have a 1640 with ECM in addition to my (much yellowed) 1512 with Hercules mod.

@@okona1up The best place to get them is the UK. But people often don't offer international shipping.

@@PCRetroTech \-: Happy brexit...

@@okona1up LOL!

The PC1512 and PC1640 are both also really nice looking machines. Amstrad was very proud of this (Lord Sugar said so) and I think they had a right to be.

Thanks.

Yeah, they seem to be really hard to obtain these days. There was a time when they seemed to come up regularly. I even managed to get a parts machine at the time.

there was a pcb assembly to display 16 shades of grey ega on the MM Version!

I didn't have GPC back in the day, but I certainly had the Amstrad. Happy days!

Oh, I initially misunderstood what you were saying. I thought this was something about the speed of the game. I see you are talking about the teams being indistinguishable without colour. Yeah, I think it is unfortunate so many monochrome displays were sold. The machine was so much better in colour. It can't have been *that* much more expensive to manufacture a colour CRT.

I also had a PC1512, though we had a colour monitor and at least at some point we got a hard drive, from memory. It's a little hard to be sure because we had a second computer eventually, and I might be misremembering the hard drive from that.

@@PCRetroTech I think misremembering happens for a lot of us. I had what I think was an AT clone after the Amstrad with a 20mb HDD and EGA monitor, then a 386 with VGA. I know for sure however, that they were always bottom of the range, a generation or two out of date, and would never run the games I wanted! Wing Commander was but a dream...

Yeah it's a shame upgrade from CGA doesn't seem to have been an option on the 1512.

Yes, that really stands out to me now. I had a PC1512 back in the day and the way the marketing worked, I just assumed an XT was faster. When I finally got an XT clone I was very disappointed to find that things didn't seem to be any faster at all. Of course back then I had no idea why this was.

That's correct. I didn't show it on video, but I appeared to have other compatibility issues. In fact it took hours to find games that I could actually show working. It's unclear why this is though. I can't believe those games didn't work on this machine back in the day. I think it is largely down to a number of possibilities: 1) Poor curation of abandonware, e.g. missing files 2) Games made to work with emulators that no longer work with real hardware 3) Games taken from demo CD's where certain features or compatibility options have been removed 4) Games taken from distributions that were (for cost) licensed to run on certain hardware only 5) Features left out or not available after being made to run without copy protection

Can still find in France for not too much

I've never seen that and don't know what that would be. Are you sure it was a real floppy drive and not some modern floppy emulator?

@@PCRetroTech This would have been around 1990, Durham University still had lots of 1512/1640 . You still got noise of drive spinning, just minus the clunking. No where near as freaky quiet as the SUN Sparc station's 3" drive

@@taichitortoise4859 You mean while the drive wasn't in use? The clunking is the heads moving, which is an integral part of the operation of the device. They are just standard floppy drives in there, so I'm really quite sure of this.

I'll have to give it a try and see what it does. Maybe it caches the directory or something, though I'm not sure how file writing would work then.

Yeah maybe now it is possible to afford a 1512DD. Many of those disks probably still work. They do come up from time to time online.

@@PCRetroTech Thinking more about this pc I didn't buy a pc1512 but a pc1640, with hercules display. It cost me about 210000 Escudos (about 1050€) in 1987.

I have an orphan Amstrad PC 1512 SD without the software. Interested in selling your 5.25's?

The planar structure of video RAM is only relevant if you are filling large areas with the same colour. For things like sprites you have to keep changing the write mask to the colour of the pixel you are trying to write as you fill video RAM (which would be slow) or you do it plane by plane, which is going to be twice as much data to put in video RAM (16 colours vs 4).

That's correct. The PC1512 did have a custom 16 colour mode.

Yes, i have one and if i remember, deluxe Paint works too, 640x200 16 colour. If my memory is correct.

I don't know. Interesting question. I think it is unlikely, as FPUs were not common back in the day, and it was assumed by most game manufacturers that a home user wouldn't have one, as they were quite expensive. But about this specific game, I don't have further information.

Sure, but they were cheap.

Unfortunately I don't have access to those at the moment, so I can't help. They do seem to come up for cheap online in the UK if you can get hold of them there though. Usually they don''t work, but if you just want to get a visual that may be an easy way.

@@PCRetroTech Thanks anyway. I just posted a request on one of the Amstrad forums so I might get lucky. Plenty of photos on the net, but all are of the front. I've seen a couple on eBay UK, but a bit pricey to get them to Australia.

@@austfox2170 Ah I see. Yes, shipping stuff to Australia is pretty expensive. If you still come up with nothing in about a week, let me know again and I'll have access again and might be able to do something.

@@PCRetroTech Someone on the Amstrad forums posted a photo within 3 hours of my request. Yay! I've recreated the disk sleeve, so if anyone can make use of it to print and make their own, head on over to the 'CPC Wiki' forums to grab the PDF file.

@@austfox2170 Great news! Glad you managed to find someone who had them to hand.

As KZfaq won't allow viewers to share links you might not get much response. However, the Internet Archive has a zip file with the system disks in case your physical disks are not working. However, you still need to get them onto 5.25" floppies for which you will need another more recent machine with a floppy drive. archive.org/details/pc1512_flop.7z/large_cd0408_002_080822_2008_33_4_Amstrad_computer_base_unit.jpg Scroll down to see where to download the disks.

@@PCRetroTech Thanks guy!!! You made my day!!! 👌

Yes, the game is also called Driller. The Commodore 64 version is a slide show, but people still loved it apparently. I don't know how they made the PC version so smooth.

@Lassi Kinnunen 81 Why do you believe that? The C64 has a dedicated graphics chip (VIC II). Although the CPU runs at a lower frequency, bus access is a lot quicker. I don't see any reason to think the C64 is much slower. Check out the C64 demos out there. There's oodles of stuff we can't do on PC or an 8086 clone machine. Yes, the 8086 has a 16 bit data bus and runs at 8 MHz not 4.77 MHz unlike the original IBM PC. Those are legitimate reasons the 1640 would be faster. But it doesn't really explain the enormous difference in performance of digger. Presumably available memory is an issue on the C64 or something.

@Lassi Kinnunen 81 I know you can use the latches for fast copy on VGA. I've never checked if this exists on EGA though. I'd be very surprised if an 8086 could do a mul that much faster than a C64, though yes it does have an instruction for it which is convenient. It has div too, but I doubt it is used at all in a really fast game like this. It is just too slow. As for shifting, the 8086 can only shift by 1 bit at a time efficiently. I don't think there is much advantage there. It's also surprising that Elite performs badly on a C64. It works so well on a BBC which is also very limited. As for the scene, there has to be a reason very little has been done on pre 286 PC's and yet so much is done on C64. I'm aware it is all trickery (and I know some of the tricks, obviously). True, real 3D rotation is hard, but we aren't talking about 50/60 fps here or even 2-frame demos. We are talking about just a few frames per second. Clearly sprites can't help, but I really don't see what would actually help on an 8086 machine with EGA. Bitplanes help a little I guess. I believe both C64 and EGA had vertical retrace interrupts, though I'm not sure whether they were used much on EGA as they were inconsistently implemented by various EGA implementations. I don't think EGA had raster interrupts though. On the other hand I am not sure if they would be useful here. Naturally Amiga is better than the C64. But this was a 16/32 bit CPU and ran quickly. It had a blitter and the like, correct me if I'm wrong. You are quite possibly right that there just aren't any tricks on the C64 that really benefit here. But I'm surprised to hear someone say that an 8086 machine does have hardware that helps. It's maybe the first time I've heard someone claim a PC of that era was better than a C64 for something.

@Lassi Kinnunen 81 Yeah that's cool if you can do memcopy on EGA. I should have tried this ages ago, since it is a question I've had for a while. Agreed, it would give you faster polygon fill. Who is the prolific author that you spoke of that moved to VIC20? I'd be interested in checking that stuff out. By textmode you mean hacked up for a 160x100 graphics mode? Or ANSI text? 8088 MPH is pretty well described as far as 3D goes on Scali's blog. They use a scanbuffer, which I think records the beginning and end of a section of a scanline that should be one colour. Then they can use a fast routine for just writing out all the bytes/words between those two endpoints. All the updating is then done to the scanbuffer I believe. On the other hand, with some of their effects it is not clear to what extent stuff is prerendered when doing 3D rotation. From some calculations and experiments I've done myself, it seems clear that one has to do at least some precomputation. 3D rotations themselves, unless fairly simplistic, have to be computed using sin and cos. Of course you can look the sin's and cos's up in a table, but the arithmetic itself using those values has to be precomputed as far as I can see. That's difficult in a game like Digger, which is precisely why I say it's impressive work. Same for Elite. The fill itself actually doesn't take that much time, though has to be very carefully optimised. The biggest problem with Digger is those very large areas that have to be filled. It is really hard to come up with an algorithm which just fills around the edges of those triangles (the regions that could have been modified since the last movement) and not in the centres, where likely nothing has changed. [One can do it in the horizontal direction ok, but for almost horizontal lines that move this will not be sufficient.] I should check out some of these games you mention. I have either forgotten some of these over the years, or never seen them before. And I love looking at games where there is convincing 3D. It is one of my current hobbies, amongst other things. One really important reason Elite was so optimised is that they used very carefully chosen data structures to store the information. These really saved a lot of bits. I am not super familiar with the BBC. I recall one of them has two CPUs (unless I've mixed that up with something else) and at least one of them uses the same CRTC as the IBM CGA card.

​@Lassi Kinnunen 81 You are from Finland, into the scene but live in Thailand!? Wow! I won't ask. Yeah Ville-Matias Heikkilä says on his site he is going to fix the world and he has relevant computer experience. Given the experiences I've had this week with automated customer service after locking me out of my accounts with a certain online financial service, I do wonder how he thinks his computer expertise will help with that. LOL. But I will watch his stuff (thanks for the references), as I somehow missed it in the 90's. Perhaps he was prominent in the early 90's. I only discovered the scene in about 95 when I got internet access having only met one scener by accident before that (I've not managed to identify him since; he was working on the 286 in Tasmania, had a lot of silver coloured text scroller effects that I remember). [In case you go looking, I still don't have any prods myself yet, though I am working on that one.] And I mainly watched stuff from the Assembly competition back then and a couple of other big ones which I've forgotten now. Revision has an Oldskool compo which has attracted little pre-286 PC stuff so far (other than Same Old Song and 8088 MPH and at least one other that I forgot the name of right now). I often wonder if it is just because it is harder or something like that. Other than these, there's basically just 8088 Domination and 8088 Corruption that I'm aware of, and a few old demos from the one-time "The 8086 Compo", which are mostly single effect "demos". Recently there was PC-jam. There's probably more I'm forgetting, but not much. So much stuff gets traced back to Trixter in one way or another as far as promoting pre-286, Same Old Song being the stand out exception that I know of so far. Can you perhaps order computer parts from Australia? That should be relatively nearby. Perhaps Japan or China are also possibilities? I guess time is also a major requirement. I can sympathise with that! I'd love to do the demo/retrocomputing stuff full time, but that is currently impossible due to work. By the way, what is isaes? I assume that was a typo, but I didn't figure out what you meant.

Yeah they work really well on the Amstrad machines.

I had it shipped to me from the UK, though I did live there once.

@@PCRetroTech Threw me off when you said "so popular over here in Europe" haha

@@dwindeyer I still live in Europe, just not the UK.

@@PCRetroTech The plot thickens

@@dwindeyer As you correctly guessed, I am Australian.

It was said jokingly, but also happens to be true. They were invented in 1981, and not by Microsoft.

@@PCRetroTech Ofc it is true, would anyone think otherwise? You think old or young live under rocks that long? Otoh, there are other problems in the world ;)