Archimedes PC Emulator PC emulators are not new, but so far they have had limited success in their job of enabling your chosen micro to run PC-compatible software. Simon Jones unveils Acorns PC Emulator package for the Archimedes range of micros to see how well it performs in action. At this years PCW Show, Acorn proudly displayed its PC Emulator package for the Archimedes range of computers, which is claimed to allow packages written for the IBM PC to run on an Archimedes. Acorn was demonstrating the Emulator running dBase III+ and Lotus 1-2-3 at the show and, as I only managed a quick glance at the Emulator then, I was pleased to get the opportunity to examine the product at close quarters. Having seen other attempts at PC compatibility, such as pc-ditto (reviewed in PCW, October) I was sceptical to say the least. The Archimedes carries on the Acorn tradition, having a lot in common with the BBC Micro and the BBC Master series. Indeed, the Archimedes will run most of the well-behaved software written for the BBC computers. However, the Archimedes and the BBC micros differ radically in the CPU they use and the amount of RAM available. Based on Acorns RISC processor, the Archimedes 440 is blindingly fast and, with 4Mbytes of memory, it is not short functions to those in MS-DOS. This is cellaneous keys between the main of space — a problem which caused the more than a little confusing if you are group and the numerics. The back- downfall of the BBC Micros. All constantly switching between PC space key [<-1 is where you would Archimedes machines come with ADFS, applications and Archimedes ones. expect it to be for a PC, at the top right Acorns Advanced Disk Filing System. of the main keyboard. But, for some This uses a hierarchical directory One other minor irritation that springs reason, the Archimedes uses the key structure much like MS-DOS, but, to mind is that, while the Archimedes marked Delete, found in the cursor unfortunately, many of the command has a keyboard laid out like IBMs AT-E, cluster, to do the work that Backspace words in ADFS are used to perform its use of the backspace key is ought to do. opposite confusing. The keyboard has 12 function keys across the top, a numeric I think Acorn could have done better keypad on the far right and a cluster of here. The AT-E keyboard layout is one cursor keys and mis of the better ones of recent years, and its a pity that the backspace and type PC.EMULATE. The program directory contained three files, EMU- key does not perform the same function loads and then counts through the LATE, ROM and DRIVEC. EMULATE is as on the PC keyboard. This is the case available memory to see how much it the main PC Emulator program and on the Archimedes keyboard but — lo can use for PC programs. The Emulator ROM is the Archimedes version of the and behold — in the PC emulator, both then prompts you to insert the MS-DOS BIOS chip on a PC. (The BIOS is the the backspace and the delete keys work boot disk. Once MS-DOS has been Basic Input Output System and is at the as they should. Backspace deletes the loaded you are presented with the core of what makes a PC a PC.) Both character to the left of the cursor and familiar A> prompt — and the these programs are written in ARM the Delete key deletes the character at Archimedes is magically transformed assembler. the cursor. into a PC. The third file, called DRIVEC, is the The Emulator package came on two CONFIG.SYS and AUTOEXEC.BAT PC Emulators part of the hard disk. To 3½in floppy disks. These contained the files work as you would expect them to MS-DOS it looks like a complete hard Emulator software and a copy of MS- and, if you include the ANSI.SYS device disk drive and functions just like one, DOS 3.21. The programs were tested driver in the CONFIG.SYS file, you have only very fast. (See Technology box.) on a prototype Archimedes 440 and a full control over, for example, the Next, the PC partition must be de- production model 310. The 440 version prompt and screen colour. The screen scribed and MS-DOS installed on it. of the Archimedes has 4Mbytes of RAM display thinks its an IBM-compatible These steps are done from MS-DOS so and a 20Mbyte hard disk, making a very CGA card and gives 80x25 text and the emulator must be loaded again. The impressive beast indeed. I particularly graphics in 16 colours but cannot cope MS-DOS disk that came with the wanted to try the emulator on the 440 to with blinking text, making the emulator contains all the DOS utility see how it worked with the hard disk. As background brighter instead. This programs. One of these is called FDISK the 440 is not yet available, I was seems like a sensible option until an and is used to describe DOS partitions. supplied with a preproduction machine. application decides to show some text There is also a batch file called The 310 is available now. It has 1Mbyte as blinking white on cyan. The Emulator HDINSTAL which will format the DOS of RAM and one floppy disk drive. You will interpret this as white on bright cyan, partition and copy all the utility files into cannot run the Emulator on a machine making the background text virtually it. This process only takes a minute or with less than 1Mbyte of RAM. illegible. two and then you no longer need the With 1Mbyte of memory, only 384k Another small point is that the colour floppy disks to, start the Emulator. can be used for your PC programs. brown is displayed as a murky sort of Typing PC.EMULATE from the Arthur Acorn claims that when Arthur version yellow, but then, IBM insists that its ' prompt will run the emulator program. 1.2 is ready (Arthur is the rather quaint yellow is in fact bright brown. You When it asks for the MS-DOS disk, you name Acorn has given to the operating cannot set the border colour either. The simply press the space bar and it looks system of the Archimedes) you should screen on an Archimedes is usually 32 first at the floppy drive and, finding no have 512k available for PC programs. lines deep, but the PC Emulator uses disk present, looks on the hard disk to The Archimedes takes some of the only the middle 25 of them. This makes find the operating system. remaining memory for the screen map, the display much wider than it is high some for its operating system, while the and could be a problem if you wanted to In use Emulator program itself uses 186k. On draw circles, for example, as they would In use the Archimedes PC Emulator a machine with 4Mbytes, however, a full come out squashed! program gives quite acceptable per- 640k is available for the PC programs. The package comes with a small formance if you dont want to go too fast. MS-DOS cant be held on the same program to install the Emulator prog- While the hard disk access is extremely disk as the Emulator programs because rams in a directory on the hard disk and fast, the computing speed is only the Archimedes uses a different disk reserve 10Mbytes for PC files. If, like average and the screen display speed format to MS-DOS. Archimedes disks me, you dont have 10Mbytes free on is slow. With, some, applications the hold 800k of data while 3½ in MS-DOS your hard disk, or you dont want to give disparity between the different speeds is disks hold just 720k. There is no half of your disk over to PC files, you more marked than others. With provision for the 1.44Mbyte standard of can edit this Basic program to reserve programs such as PC Outline you get a Apricots Xen PC/S machines or IBMs less space. The program has enough performance on a par with that of a PS/2 models 50, 60 & 80. Those comments in it to work out what is cheap PC clone. With dBase Ill Plus you machines can, however, write 720k happening and change the amount of tend to notice, when requesting a disks and all software distributed on space to be reserved. There are record from a file, that the disk drive 3½in disks will be in 720k format. warnings about sticking to an integer light blips on for a fraction of a second If you want to transport data from 5¼in multiple of the cluster size, but if you and the screen display takes about five MS-DOS disks to 3½in MS-DOS disks, use nice, easy figures like 2½ or seconds to complete. But dBase III Plus then youre going to have to buy an add- 5Mbytes, you cant go far wrong. does not have a fast screen display, on drive or a serial cable and some I encountered an extra problem with even on an 80286 machine. communications software. As far as I the installation in that, although I had Most applications will probably run know there isnt an add-on 5¼in drive 5Mbytes free, it was not all in the same with acceptable speed providing you available for the Archimedes yet, but place.