01659@AECLCR.BITNET (Greg Csullog) (06/09/89)
Atari programs that use GDOS write device independant output files called metafiles. GDOS takes these files and in conjunction with nonscalable fonts and device drivers, it maps the metafile to physical output devices like printers and plotters. GDOS, unfortunately, slows down some GEM functions like windows. Since GDOS has to be loaded into memory when the ST is booted and remains in memory during a session, this speed deterioration lasts even if you use a program that does not use GDOS. G+Plus, a third party replacement for GDOS, overcomes the speed problem and is worth buying if you use GDOS prg a lot (EASY DRAW, TIMEWORKS DTP, MS WORD). When you boot and load GDOS, it looks for a file called ASSIGN.SYS that tells GDOS where to find fonts. When you run a GDOS requiring program (like EASY DRAW) then the fonts are loaded from the path specified by ASSIGN.SYS. Since only one ASSIGN.SYS file is read in at boot up, all GDOS requiring programs will share the same fonts (if you have TIMEWORKS DTP fonts specified in the ASSIGN.SYS file then EASY DRAW will use them). G+Plus lets you choose different ASSIGN.SYS files on boot up, GDOS does not. Some good ST programs that use multiple fonts do not use GDOS and its fonts. Examples are SIGNUM2, CALAMUS and PUBLISHING PARTNER (does PAGESTREAM use GDOS fonts?) The advantage of GDOS over POSTSCRIPT for outputs is speed. A typical page from EASY DRAW or TIMEWORKS DTP to an SLM804 is < 60 sec. The same page to ULTRASCRIPT, the ST's POSTSCRIPT clone, will take much longer. However, the quality of the output will be much better with ULTRASCRIPT. With Revolver, I can divide up my Mega's memory and run more than one appl. at a time. Unfortunately, I can not run Spectre or PC Ditto in one partition and GEM codes in another since both emulators cannot handle the Revlover environment. IF THEY COULD!!!!, I could run PC codes, Mac codes and GEM codes AT THE SAME TIME and switch between them. Too bad this cannot be done yet (if ever) but it would be nice. Finally, Amiga vs ST. The Amiga uses memory paging. Eveything above 512K is not main memory but paged memory. Since the Mac needs continuous memory, the Amiga version of a Mac emulator cannot run in more than 512K of memory. Therefore, unlike Spectre which gives me a 1.7 meg Mac, the Amiga-Mac has limited capability (at least that's mu understanding of the situation).
aegnor@bsu-cs.bsu.edu (David C. Powell) (06/10/89)
>Finally, Amiga vs ST. The Amiga uses memory paging. Eveything above 512K is >not main memory but paged memory. Since the Mac needs continuous memory, the >Amiga version of a Mac emulator cannot run in more than 512K of memory. ^^^^^^ ^^^^ >Therefore, unlike Spectre which gives me a 1.7 meg Mac, the Amiga-Mac has >limited capability (at least that's mu understanding of the situation). <BEEEEEEP> Wrongo! ;-) I own an Amiga, and am going to be buying the Mac emulator "AMAX" , I am in 'touch' through the net with people who own "AMAX" and it *CAN* address more than 512K of memory, I have an article buy the 'author/designer' of "AMAX" and in it he explains that he "tricked" the operating system of the MAC/Amiga into believing that ALL memory is continuous memory! So far, everthing productivity wise that has been tried has worked (ie. Hypercard that requires a Meg (?) and several others like Excel are reported to be 'running fine') sooo.... Amax can and DOES work with as much memory as you can throw at it... the only thing he KNOWS of that cause problems (running problems that is..) are certain games that do undocumented/illegal calls to the OS/Hardware and some MIDI programs also bomb... As a future (ahh, for my savings to accumulate :-) ) Mac emulator owner, what do YOU people know of that does NOT work with the Spectre/Magic Sac emulator, and where would I go to find *GOOD* /useful PD DA's games etc. !!! Thanks!!! David C. Powell M.I.S. Senior Atari 8-bit owner & Amiga owner Ball State University Muncie, Indiana *-David Powell :ARPA: aegnor@bsu-cs.bsu.edu--------------------------* | \/ President :UUCP: <backbones>!{iuvax,pur-ee}!bsu-cs!aegnor | | /\etwnk Industries, Ltd. : | *-"If it doesn't work, we DIDN'T do it!"-----------------------------*
dlm@druwy.ATT.COM (Dan Moore) (06/12/89)
in article <8906090028.AA08920@ucbvax.Berkeley.EDU>, 01659@AECLCR.BITNET (Greg Csullog) says: > Finally, Amiga vs ST. The Amiga uses memory paging. Eveything above 512K is > not main memory but paged memory. Since the Mac needs continuous memory, the > Amiga version of a Mac emulator cannot run in more than 512K of memory. > Therefore, unlike Spectre which gives me a 1.7 meg Mac, the Amiga-Mac has > limited capability (at least that's mu understanding of the situation). The Amiga does not use paged memory. It's just that not all memory is located at consecutive addresses. After the first 512K or 1024K of "chip" RAM (Amiga display RAM) there is a large gap before the next block of RAM. This is a big difference from the ST and Mac which assume all memory is in one block starting at address 0. AMAX (the Amiga Macintosh emulator) has some advantages and disadvantages vs. the Spectre. AMAX can support more memory (> 4 meg) and can run faster (if you have a 68020 or 68030 in the Amiga). The Amiga doesn't have ROM in the first 8 bytes of memory so Mac programs can write there without generating a buss error. The Amiga hardware can also read part of a Mac disk directly, no need for custom disk interface hardware (Spectre GCR or Translator One). The biggest disadvantage is lack of hard disk support, unlike the ST there isn't a standard hard disk interface on the Amiga, all the hard disk controllers have different interfaces. (Of course the Magic Sac was out quite a while before hard disk support was added.) Also there is some loss of compatibility when running AMAX and using the non-contiguous RAM since the Mac assumes all memory is located in one large block. Dan Moore AT&T Bell Labs Denver dlm@druwy.ATT.COM