★ HARDWARE ★ THE ROM RANGER (AMSTRAD ACTION)|Amstrad Action) ★ |
| The ROM Ranger (Amstrad Action) |
One of the most wonderful features the CPC's designers included in the system is its ability to access programs stored on external ROM chips. It's so fast to enter these programs from the keyboard that even disks look snail-like by comparison. PHIL CRAVEN, the ROM ranger himself, investigates. OM stands for Read Only Memory. Unlike disks and tapes you can't alter what's on them -but then, you wont want to. They are quite literally memory extensions, with the computer's operating system containing all the software needed to use them. Access is virtually instantaneous. A few key presses and there you are: the program you want up and running. The only real disadvantage, in fact, is that you dont get time to put the kettle on. You can add up to seven of your favourite or most often used programs -disk utilities, word processor, assembler, general utilities, disk operating systems or whatever - if you have a 464 (including the disk drive ROM), and up to 15 for the 664 or 6128. One obvious choice is to have your word processor on ROM, so that when you stagger to your desk first thing of a morning or after you come home from a long day at work, you can simply sit down, turn on and get going. None of this Tm sure I left xxx The usual thing to do is to buy your ROM ready 'blown' or 'burned', which simply means with your software on (think of it like buying a record, which has been 'cut1 and which can't be altered - only damaged!), from a mail-order firm or the occasional specialist computer shop. Try looking in AA adverts. Once you have your ROM, which looks rather like a plastic centipede with metal legs, a ROMboard, with ROMs inserted, has to be connected to the 50 way expansion port. But which do you buy? Will this board work on that machine? And why the differences in price? Each has its own features, facilities and prices, and it is for you to make your own choice according to your needs. To give you the information needed to make that choice, we gather here for your delectation all the currently available boards. Others have come and gone, such as the Brittannia, but so far as we know we present all the current ones on these pages. (A termer is on offer to the first person who comes up with the details of commercially available boards not covered here!) Handle with care ROMs, and other chips for that matter, are sensitive creatures. Some are susceptible to damage by static electricity: never touch the pins. And always insert them the right way round according to the instructions supplied with the board. Some final points to bear in mind:
MICROGENIC Bristling with features. Microgenic's board has eight sockets that can be set to high or low groups; each ROM has an enable/disable switch: and it has a Reset button. Its own unique contribution to ROMboard design is its overall enable/disable switch. Lots of software wont run if too many ROMs are fitted, and this extra switch disables or enables the entire board, with an LED indicating status. The time consuming option would be to power down, remove the board and power up before starting again. Size: 6.75' x 5.75' : uncased: connects vertically to the computer. KDSBOARD A compact six socket board, housed in a white plastic box and connected via a ribbon cable. Each socket has its own enable/disable switch. Its slots are fixed at 1 to 6 with no option of setting it to the high group. Dimensions are 3.75' x 3.5' x 1.25' , but it's not size that mailers. The KDS board is not rigid inside its box. and although at first I didn't approve, I've since realised that flexibility when the computer moves is a Good Thing.
JOHN MORRISON EXPANSION BOARD Another four socket board, perhaps best suited to the DIY enthusiast, since the facilities i: offers are implemented with a soldering iron. Not only that, but it's cheaper :o buy it in ki: form. Its slots are fixed at 1 to 4, it is uncased, measures 5" x 2.75' and fits vertically to the computer. Normally all boards take 8K and 16K ROMs, but this is one of two that also take smaller ones. Both boards are available in «it form and it is because the user is likely t.o be good with a soldering iron, and the smaller chips need a modifica- i tion to the board,' that the facility is included. No commereial ROM software is available on smaller chips but the feature can be used for ROM developement. The instructions include a modification for adding a second board to run slots 9 to 12 MAPLIN'S EXPANSION SYSTEM The other board (with John Morrison's) available in kit form, it has eight sockets, low bank only, and is housed in a two-tone grey and aluminium box measuring 8' x 5.5" x 1.5'. Connection is via a ribbon cable and it incorporates many of the features found in the other boards. The eight enable/disable switches, the two through connectors and the small chip capability arc all included. To call it a ROMboard, however, is an understatement. It includes a light pen socket, buffered decoding for up :o 128 I/O addresses and a one meter 50 way ribbon cablo and socket for connection to a Eurocaid motherboard, which can accomodate six plug-in modules. To make full use of the I/O addresses and motherboard an additional power supply is needed which Maplins supply in kit form or ready made. This board probably suits the DIY person both because of the expansion possibilities, and because none of the sockets work without a little soldering of links.
ROMBO BOARD Probably the best known of all, the Rombo lakes up to eight ROMs, configured to either the low or the high group. Each can bo enabled/disabled by its own switch in a row of eight, although this is inconvenient for frequent use as the board is enclosed in a black plastic box measuring 4.75' x 3.75' x 1.75". Connection to the computer is via flat ribbon cable. The two through connectors provided are a bonus. A unique feature is tha: slot one is extended to a small edge connector for the addition of either a RAM/ROM (£19.95) or a ZIF (zero insertion force) socket (£14.95). The Rombo is now the only board to which a RAM that behaves as a ROM can be connected. The idea is to load the RAM with a ROM type program and, as long as the power is kept on, it then behaves as a ROM. The ZIF socket simply allows a ROM chip to be inserted and removed without friction. Though most users wont want to remove ROMs from the hoard, there are occasions, to avoid clashing with the ROM in a new peripheral for instance, when you might want to. It's possible, but it's not easy Sockets are so close together and low dowr in the box that it is hard to get a screwdriver under a chip, and an extracting tool can't get between them either.
CIRKIT HX-RX1 ROM EXPANSION CARD Measuring only 4" x 2.75', it connects with a ribbon cable and has just four ROM sockets which can be configured to be in the low/high group. Associated with each socket is a bank of eight links representing slots 0 to 7 or 8 to 15 depending on the group selected. By positioning the links each socket can be mapped to any slot number and. uniquely, the position of each ROM, within the group, can be changed without even touching the chip itself. The unit is supplied uncased - fair enough at the price, though it means that its underside, where all the pins are, slides across a desk if the computer moves. This can cause scratches and 1 would recommend the fitting of plastic feet, which cost only a few pence. Suitable holes to fit them already exist in the board. ROMBOARD XTRA Two unique features: it only fits the 464. since the 664 and 6128 monitor leads get in the way; and one of its seven sockets :s set aside for inserting the 6128 system ROM and thereby upgrading the 464. It is uncased, measures 6.5' x 2.75' and fits vertically. ROM slots are 1 to 6, low bank only. Each socket has its own enable/disable link and a reset button is incorporated to reset the computer when the three finger trick wont work. One socket is designed to take the 32K 6128 ROM. and a switch is included to change between the 6128 and 464 systems. With the 6128 ROM. a 64K expansion memory and a disk drive fitted, the 464 is effectively upgraded to the 6128 specifications. Note: some 464s were made with their ROMs in sockets which only need removing to insert the 6128 ROM. Failing that, this method of upgrading is simple and effective.
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