The single most often asked question about 1286/2286/1386/2386/3286/3386/4386 is where can I get a copy of the Setup program because the batteries have gone flat and I've lost the original disk. For 3xxx and 4xxx you press Ctrl-Alt-S at the DOS prompt but for earlier PCs you need a separate program - well, here it is...

A common question is how to add one of the modern, large (say 512M or 1G) drives to our older AT class PCs such as the 1xxx/2xxx/3xxx. This is eminently possible, You just unplug the existing WD1006V card and plug an IDE controller in its place and then remove the existing mechanism and fit one of these racy new ones in it's place.

Of course, that's only half the story. The next question is how do I get the BIOS to support the new, large drive. There are two possible solutions to this. One is to upgrade from the 1.xx BIOS fitted in 1/2xxx to a 2.xx as fitted into the 3xxx series and onwards. However this may cost about £60 ($100). A cheaper alternative is to get an "intelligent" IDE controller which only costs a few pounds more than a standard one. It's intelligent because it has its own hard disk BIOS with user settable parameters on the interface card and this over-rides the internal hard disk support of the motherboard BIOS.

The following is an application note I wrote about this which basically regurgitates the 2286/2386 manual. The 3286 and 3386SX links are the same as shown for 2386. The 3286 can use the intermediate sizes shown for 2286 but using the 2386 LK numbers (if that makes sense!?!)

From    :  Amstrad Plc
Subject :  Adding memory


				  Upgrading Memory - PC 2286 / PC 2386

Memory upgrades may be fitted to the PC 2386 and PC 2286 by inserting
appropriate SIMM (Single Inline Memory Modules) into the sockets provided.
You should obey the following rules:

* PC 2386 must have four modules, each of the same size, fitted.

* The PC 2286 may have one or two pairs of modules fitted. In the table
  below, the first named pair is fitted to the innermost two sockets.

* Beware, the size of SIMM may not be the same as the DRAM chips fitted
  to it.	For example, a 256K SIMM may be constructed from two 1MB and one
  256K DRAM, instead of nine 256K DRAMs.

* If your PC 2286 is supplied with twelve DRAMS fitted into DIL (Dual
  In Line) sockets on the motherboard - with all four SIMM sockets empty -
  then that memory must be removed and discarded before an upgrade can be
  made.

* The DRAM speed option links must be adjusted to the speed of the
  slowest RAM fitted

						  Size Option Links
						  =================

		 SIMMS			    PC  2286				  PC 2386
					 LK20  LK19  LK18  LK17	    LK22	LK21  LK20  LK19

512K   2x256K + 2xEmpty	  In    In    In	Out
640K   2x256K + 2x64K	  In    In    Out	In
1MB	  4x256K			  In    In    Out	Out		In	 In	  Out   Out
2MB	  2x1MB  + 2xEmpty	  In    Out   Out	In
2.5MB  2x256K + 2x1MB	  Out   In    In	In
4MB	  4x1MB			  Out   In    In	Out		Out	 In	  In    Out
8MB	  2x4MB  + 2xEmpty	  Out   In    Out	Out
16MB   4x4MB			  Out   Out   Out	Out		Out	 Out   Out   Out


					 Speed Option Links
					 ==================

				    PC 2286		PC 2386
				   LK21  LK22	    LK23	LK24

	   80nS		    Out	Out		Out	 Out
	   100nS		    In	Out		In	 Out
	   120nS		    Out	In		Out	 In
	   150nS		    In	In		In	 In

For the 4386SX I'll just summarise the manual which says:

You must use four identical sized SIMMs. They are 30 pin SIMMs with
parity (ie 3 or 9 chip). Use 80nS..150nS devices.

					 LK27  LK28  LK29  LK30
1MB	  4x256K			  In    In    Out	Out
4MB	  4x1MB			  Out   In    In	Out
16MB   4x4MB			  Out   Out   Out	Out


				   LK25  LK26

	   80nS		    Out	Out
	   100nS		    Out	In
	   120nS		    In	Out
	   150nS		    In	In

The 2386 had a slight defect in it's mouse interface. It was designed to be compatible with the Microsoft Inport mouse but while it works exactly like it there is one small difference. When MOUSE.COM or MOUSE.SYS is first loaded it tries to find the attached mouse by giving it a poke with a sharp stick and waiting for it to go "Eek!". Unfortunately the mouse interface in the 2386 is a little too docile and the MOUSE.COM doesn't wait long enough for it to respond (even though we are only talking about a fraction of a second!). It then moves on to the next interrupt level and tries again until it finally exhausts all interrupt levels and produces the error message "interrupt jumper missing". This is the ONLY known error in the 2386 mouse system. If you have some other symptom then what follows doesn't apply to you.

The answer to this problem is actually fairly simple. If only the Micrsoft MOUSE.COM or MOUSE.SYS program can be persuaded to wait a bit longer while looking for the mouse interrupt level everything will be fine. The solution is at hand in my file archive. I have written a program called MouseFix that you run just once and it actually modifies your copy of MOUSE.COM that came from Microsoft on the Windows 3 disks. It adds a delay into the detection process so that the mouse WILL be found. As it is modifying Microsoft's file it is a good idea to make a back up before proceeding!

1/2/3xxx Video DIP switches (x286/x386 only)
============================================

Sw 1 On = Multifrequency monitor attached
Sw 2 On=PS/2 mode, Off=AT mode
Sw 3 Unused
Sw 4 Off/On = 8/16 bit bus interface

The switches were all for compatability during the transition period
from EGA to VGA usage and as such are mostly irrelevant these days. I
think I'd probably go fr a default of Sw 1 On, Sw 2 On, Sw 4 On.

Option links for 1/2/3xxx (but not x086s)
=========================================

9-12 Mouse IRQ on 5,4,9,3
19-22 RAM size (detailed separately)
23-24 RAM speed (detailed separately)
27 enable onboard HD controller (disabled on 2386)
28 enable onboard VGA
30 enable onboard Mouse interface
31 enable onboard parallel printer port (LPT1)
32 enable onboard Floppy disk controller
33 enable onboard Serial interface (COM1)
34 enable Power On Self Test
36 enable expansion bus cache

Most of these links are accessible by removing the metal plate from the
bottom of 1/2xxx machines or are easily visible on the system board
inside 3xxx machines. The mouse IRQ links in 1/2xxx are very difficult
to get to (requires complete disassembly!) but should never need to be
changed.

Option links for 4386SX
=======================

10-13 Mouse IRQ on 5,4,9,3
14 speaker volume (1+2 = loud, 2+3 = quiet)
27-30 RAM size (detailed separately)
25-26 RAM speed (detailed separately)
24 enable onboard HD controller (disabled on 2386)
23 enable onboard VGA
20 enable onboard Mouse interface
19 enable onboard parallel printer port (LPT1)
18 enable onboard Floppy disk controller
17 enable onboard Serial interface (COM1)
16 enable Power On Self Test
33 enable expansion bus cache

I'm indebted to Bob Morris for sharing the following information with me for inclusion in these pages: