Rybags

Not to mention the interface to the drive itself likely being very different. And in the pre 1.44 meg days their disk format was also different... might be wrong here but I'm fairly sure their early drives used different speeds depending on what track was being accessed. Mac drives originated in the days where every man and his dog created their own "standards". Sure, it would be theoretically possible to interface a Mac drive to the ST but would likely cost a fair bundle, and you'd be in a situation where your disks would be good to you only. Just better off getting a HDD or one of the SD-card based floppy replacements.

Another thing you could try, if you have an Atari cassette recorder: See if an audio tape will play through the TV speaker - if it does, then that would likely mean that Pokey or something in the path from it to the audio mixing is faulty. Type CLOAD from BASIC or just POKE 54018,52

As usual, you didn't bother to read the thread properly.

You'd need games with specifically made loaders because you need to have the cartridge disabled at first. Then it would prompt the user to switch the cartridge "On" and at that point it could run the game. I expect that the "Super Pill" probably automates the process - in theory they could just have added some extra circuitry so that the write protect could be switched by software instead of manually. I don't know if there's any games downloadable that could run with The Pill. I guess it would be easy enough to write a loader that'd let you try out 8 and 16K non-banked cartridge images with it though.

Quick answer - it allows part of your computer's RAM to act like ROM. Long answer - you can copy A8 cartridges by hotswapping them into the machine and using a previously loaded program to write them to a disk file. Then you can load them into RAM - since the addresses used by cartridges are the same as high memory in a 48K system, you can run non bank-switchable cartridges from RAM. It didn't take the games makers long to catch on, so most game cartridges have hidden "self destruct code" that writes to addresses within the ROM space, which does nothing if running from ROM but will corrupt a RAM-based copy to the point where it'll either be crippled or just crash the system. The switch on The Pill allows you to load such a cart copy, then it should prompt the user to switch it on which should write-protect the RAM area from $8000-$BFFF It's also of use to cartridge developers - you can simulate a 16K ROM environment to test your programs during development. But of course in this day of emulation, plus the fact that practically every game from the old days was cracked, it's not so relevant. The cartridge itself isn't anything revolutionary - I don't have one but would guess that all it does is detect if a Write operation is being attempted to $8000-$BFFF, and if it is, it triggers the relevant cartridge control lines to make the system think that a ROM is present there. In doing so, that inhibits the access to system RAM, and the write occurs to the non-existant ROM on cartridge.

There's arcade supply sites that sell them for under a buck each. Don't fall for the scammers - I've seen "auctions" that include printed instructions, 2 chips and are asking over $20.

Breakout cable gives you the individual signals from the monitor port so you can connect to monitors like the 1084, or connect to A/V on a TV. 600xl.zip Schematics for the 600XL are there. The locations of chips on the board are generally marked with letter "U" followed by a number. Actual chip identification is usually by the full "CO" code. A fairly complete list is here http://www.best-electronics-ca.com/custom-i.htm Since you have a sound issue, the main interest would be Pokey and the sound circuit. You might start by getting an oscilloscope and monitoring the Audio Out pin of the monitor port while letting the Sound Test run. GTIA generates the speaker click, it's mixed into the audio. You also might want to directly monitor the audio out pin of Pokey as well.

You'd have been better off getting or making a breakout cable to get the signals from the monitor port. Don't suppose you have an oscilloscope - would make diagnosing this a whole heap easier.

I've not had XEGS switch problems, but I can say that the switches used on the 7800 are utter crap. Chances are if you source some through "Atari suppliers" that you'd be getting a modern-day best match equivalent anyway.

Measure the spacing of the pins that are soldered in, then just get some similar momentary switches of the same type/size. Chances are you won't find an exact match but there should be switches out there that are close enough. If the new ones are too tall you could probably trim a bit off the pastel buttons, if they're too short you could just glue bits of plastic on top so the buttons still work with them.

INPUT #dev,A$ for text should be fine. But the file should have <return> CHR$(155) characters. You can also have comma seperated values but need to be careful to keep the types the same. Generally it's best to just use strings then convert to numeric where relevant.

You should hear a click through the TV as characters appear when you type. If you don't, then it's probably not your sound chip at fault because keyclick sound comes from a different IC.

Don't use the keyboard test, I meant let it go to Basic. The keyboard test doesn't produce a click.

Do you get keyclick through the TV? If not then it's most likely a tuning issue (RF) or something wrong with the cable if using the monitor port.

You can play digitized sound on Ch 3 and 4 which also control the SIO bitrate because the serial I/O part of Pokey ignores what's in AUDCn. I've played around with it a little and I think Heaven did a fully-fledged digital player that worked whilst loading. Doing more than 2 channels of digitized playback at decent quality would likely need a custom SIO routine, probably operating in polling mode. The other problem is that even in silent mode, you still get some SIO noise which does interfere to a degree with whatever sound playback you want to do.

Why would your TV not work with it if it does NTSC? As long as it can tune into analog signals on the VL band, then it should work.

What's with the glitches - does ORIC use bit 7 as some attrib flag or something?

All Antic access is treated the same. The /HALT line is part of the logic and is used to determine if it's the CPU or Antic that is performing the access. The banking isn't totally "seperate". You have the narrow choice of having neither, either or both CPU/Antic using extended RAM for $4000-$7FFF accesses, and the bank you select for that applies to both. The problem with yet another banking scheme is that it becomes yet another banking scheme, which won't be supported by legacy software. It would have been nicer if a PORTC type arrangement was used from the word go with the XE, then 90% of these problems would never have existed.

The "expand > 16 lines" thing works because you keep changing the VSCROL value so that the comparison fails. Fairly sure DCTR always uses 4 bits, since you can cause "strange" behaviour by using larger VSCROL values in a normal setting, ie without the constant changes on the fly.

If you goto http://www.virtualdub.org you can download the Altirra package, it's got a hardware manual and it explains 2 aspects of VSCROL tricks - Repeating bitmap lines and shortened characters. The third trick is repeating characters or lines indefinately. It all works due to the way Antic deduces whether it needs to start a new graphics line fetch or not. By changing the VSCROL value on the fly with Vscrolling enabled, you can alter that behaviour. The way you construct your screen is typically different to what you'd think is logical. For the first 2 tricks, you alternate between VScrol enabled and a normal mode line. A "normal" mode line that's had a Vscrolling line before it means "end of Vscrolling zone". The way Vscrolling works is - For the first mode instruction of a zone, Antic sets it's internal DCTR to whatever value is in VSCROL. Then it increments it until it is equal to however many scanlines that mode is supposed to show. So, unless VSCROL=0 that line will be shortened. The remainder of instructions in a zone before the "non-VScrol enabled" line, Antic just shows them as normal. Of course, they appear to be scrolled because the first line is usually shortened. These type of lines we typically don't use when doing VSCROL tricks. For the last line in a zone, ie the one without VSCROL bit set after one or more lines with VSCROL bit set: Antic sets it's DCTR to 0 then counts it up until it reaches the value in VSCROL. So, by altering VSCROL at strategic times, you can create shortened lines or extended ones. The downside using it with character modes e.g. 6 pixels high instead of 8, is that you need to have 2 custom character sets because half the characters lose the top 2 pixels and the others lose the bottom 2.

You can cover the whole screen. IIRC, you use the mode line with Vscrol bit set, then the next one with VScrol not set (end of scroll-region) Since Antic does the "Is DCTR = VSCROL" comparison to decide if the line has finished, all you have to do is keep changing VSCROL such that the comparison keeps failing.

I'd forget about stuffing around writing floppies on a PC drive. If you're going to put a USD into the 1050, then you'd obviously have the skill to build your own APE interface. You could even build it into the 1050 - it's just a 1489 RS232 level convertor IC, resistor, diode and cap that can fit on a circuit board smaller than a matchbox.

Defeating badlines means you can preload colours and even do midline changes. First line doesn't matter, you could just leave it blank. Also you could disable DList DMA after the initial LMS - in that case Antic will just repeat whatever mode you're in.

The topic is only about ST in monochrome mode, I only listed stuff relating to colour as comparison. ST in colour mode is essentially the same as normal TV except for "no interlace" - hires mono is way different.

The whole conversation was assuming a VGA capable monitor to begin with. And ST colour modes, like most old computers, isn't interlaced, it's just progressive 15 KHz.