Running the Altair SIMH from.net programs

Transcription

1 Running the Altair SIMH from.net programs The Altair SIMH simulator can emulate a wide range of computers and one of its very useful features is that it can emulate a machine running 50 to 100 times faster than the real machine ever did. This means the SIMH can be used to perform tasks like compiling. One important variable when writing code is the time to write/compile/edit/write, and the SIMH allows this to be reduced to one keypress and 8 seconds or less. Every program has its strengths, and the SIMH s strengths are the enormous power of batch file programming..net programs, such as VB.Net have the advantage of Rich Text boxes, which can display coloured text for syntax checking, and allow copy and paste. If you are writing some new software in VB.Net, wouldn t it be handy to compile it on a SIMH with one keypress? Steps to do this are: 1) Run a batch file that runs the SIMH 2) Load a parameter file that acts as a Telnet host. 3) Run a Telnet client on vb.net and connect to the SIMH 4) Use a little program (on the disk images) called R.COM that reads a file from the local PC directory into the SIMH current disk. 5) Run a program eg a compile. 6) Use another little program called W.COM to write the compiled program back to the PC directory. You can also then automatically run Xmodem to transfer this file to a real CP/M computer and run it. This article does not deal with this aspect, though a working program is available for free here Let s start with collecting some files. You will need: The Altair image files. Download individually from the SIMH site. Or download a package of 8 disks and all the associated files from the wiki site above. Extract to a directory called c:\n8vem\altairsimh. You can change this in code down the track. Download the free Dimac Telnet interface package w3sockets art.asp Or from the wiki site. Download vb.net from Microsoft You will need the Dimac w3socket installed. Unzip the Dimac file and run the install file. Also, copy the file socket.dll to C:Windows\System32 or wherever your

2 .dll files reside. The location is not that important for the.dll as you will point vb.net manually to the location. Fire up vb.net with a File/New Project/Windows Forms Application. It should look like this: Use the toolbox on the left to add a TextBox and a button. The textbox will be called TextBox1. Change its properties on the right panel to Multiline=True and you will be able to make it taller. Change the text on the button to Compile. Make the form a bit bigger. You should end up with this: Now follow these instructions to register the sockets.dll that you saved earlier. ' run the SocketReg program 'Your application needs to be aware of the socket.dll file, I accomplished this as follows:

3 '1. Click on the 'Project' menu and select 'Add reference...' '2. Click on the 'Browse' tab '3. Navigate to where you have socket.dll installed on the HD '4. Select this file and click 'OK' Next, lets go into the code view (top right corner of the screen, second from the right = view code and paste in some code. The font is tiny so lines don t wrap. Imports System.IO Imports Strings = Microsoft.VisualBasic ' so can use things like left( and right( for strings Public Class Form1 ' ' Get the free download called w3sockets half way down the page ' put the sockets.dll file in c:\windows\system32 ' run the SocketReg program 'Your application needs to be aware of the socket.dll file, I accomplished this as follows: '1. Click on the 'Project' menu and select 'Add reference...' '2. Click on the 'Browse' tab '3. Navigate to where you have socket.dll installed on the HD '4. Select this file and click 'OK' Private WithEvents w3sock As Socket.TCP ' needs Public Declare Sub Sleep Lib "kernel32" (ByVal dwmilliseconds As Integer) ' for sleep statements Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load ' startup w3sock = New Socket.TCP Sub CompileSIMH() Dim Location As New Process Dim Filename1 As String Dim i As Integer Dim SBasicFile As String SBasicFile = "NEW.BAS" Try TextBox1.Text = "" TextBox1.Refresh() Filename1 = Strings.Left(SBasicFile, Len(SBasicFile) - 4) FileCopy("C:\N8VEM\" + Filename1 + ".BAS", "C:\N8VEM\AltairSIMH\" + Filename1 + ".BAS") Location.StartInfo.FileName = "AltairAllTelnet.bat" Location.StartInfo.WorkingDirectory = "C:\n8vem\AltairSIMH" Location.Start() ' shell the batch file w3sock.timeout = 5000 ' long enough to do a compile for a big program? w3sock.dotelnetemulation = True w3sock.telnetemulation = "TTY" w3sock.host = "Localhost:23" w3sock.open() w3sock.sendtext("d:" + vbcr) ' change to drive D where sbasic is Sleep(200) w3sock.sendtext("r " + Filename1 + ".BAS" + vbcr) ' copy to the simh from pc directory Sleep(200) w3sock.sendtext("sbasic " + Filename1 + vbcr) ' run sbasic ' will take longer than this w3sock.waitfor("d>") ' wait for the D> prompt to come back Call RefreshTextBox1() ' display error messages etc as they come in For i = 1 To 2 w3sock.sendtext(vbcr) ' in case hangs send a few CRs Sleep(200) Next w3sock.sendtext("w " + Filename1 + ".COM" + vbcr) ' write back to PC directory RefreshTextBox1() For i = 1 To 2 w3sock.sendtext(vbcr) ' in case hangs send a couple of CRs Next ' erase the files on the simh otherwise fill up the 1mb disk image w3sock.sendtext("era " + Filename1 + ".BAS" + vbcr) ' so don't clutter up simulated drive D Call RefreshTextBox1() w3sock.sendtext("era " + Filename1 + ".COM" + vbcr) 'now halt the simh program w3sock.sendtext("halt" + vbcr) ' halt the simh Call RefreshTextBox1() ' now copy file to c:\n8vem FileCopy("C:\N8VEM\AltairSIMH\" + Filename1 + ".COM", "C:\N8VEM\" + Filename1 + ".COM") Kill("C:\N8VEM\AltairSIMH\" + Filename1 + ".BAS") ' clean up Kill("C:\N8VEM\AltairSIMH\" + Filename1 + ".COM") ' clean up w3sock.close() ' close the socket Catch ex As Exception ' errors eg if it didn't compile so there is no file to copy

4 w3sock.close() ' close the socket TextBox1.Text += vbcr + "Syntax error - aborting" + vbcr TextBox1.Refresh() TextBox1.SelectionStart = TextBox1.TextLength TextBox1.ScrollToCaret() End Try Private Sub RefreshTextBox1() TextBox1.Text += w3sock.buffer TextBox1.Refresh() TextBox1.SelectionStart = TextBox1.TextLength TextBox1.ScrollToCaret() Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Call CompileSIMH() End Class Ok, now we need a program to compile. Copy the text below into a program called NEW.BAS and store it in a folder C:\N8VEM comment commentline commentline end rem *** functions and procedures *** rem ************ MAIN ************** print "Hello World" end If you got the Altair files from the SIMH site you will need to put all the individual files in a folder C:\n8vem\AltairSIMH and there are a couple more things to do. (If you got them from the wiki this has all been done). First, we need a batch file called AltairAllTelnet.bat which contains just one line altairz80 telnet Then we need some.dsk images, and these need to be in the right order as we are going to disk D which has Sbasic to do the compiling. The file is called Telnet and it has no extension. These files are a bit hard to edit on a PC you need to change the extension to.txt, edit that, and then change it back. The file Telnet looks like this: set console telnet=23 d tracks[0-7] 254 attach dsk cpm2.dsk attach dsk1 basic.dsk attach dsk2 games.dsk attach dsk3 sbasic.dsk attach dsk4 supercalc.dsk attach dsk5 tools.dsk attach dsk6 wordstar.dsk

5 attach hdsk i.dsk set cpu 64k set cpu noitrap set cpu z80 set cpu altairrom set cpu nonbanked reset cpu set sio ansi set sio nosleep boot dsk bye And this tells the Altair simulator what to do. It attaches a whole lot of disks (in order of ABC etc so A is CPM2, B is basic.dsk (Microsoft basic) and D is sbasic.dsk. It sets the communications to Telnet. It boots into CPM and then waits till CP/M runs a program called HALT.COM (on the CPM2 disk) which then jumps to the next line in this batch file which says Bye and shuts down the window. If you want to type commands in the altair simulator manually, copy the file Telnet to something different, and leave out the first line Telnet. There are more disk images at the SIMH site. Now if you go back to vb.net and run the program, and click on the Compile button, the text box should look like this:

6 If it doesn t work, try deleting the Try and Catch as Exception, and then it will error and vb.net will display the actual error. There are a few little tricks with the vb.net eg the short 100 millisecond delays after sending a command before waiting for a response. The w3sock.waitfor sometimes waits for a > and sometimes a D> because that is drive D and indicates the program has finished. You could change that to A> for example. The w3sock.buffer is a bit tricky. It has a maximum of 8192 characters and you can t clear it manually. If you read it too often it prints the same characters over again. So you only read it as infrequently as possible, but not so infrequently as to miss characters. In any case, it does still miss characters with a big text dump from a large compile because you can t split that up. Sometimes you need to send a few carriage returns to make sure a program has finished. So there is a bit of tweaking to do, but basically you send a command and then wait for something to come back that you know is the end (which is usually a >). There are all sorts of compilers on the SIMH site and on other sites Fortran, C, Forth, Microsoft Basic etc. This demonstration is part of a larger program that is an Integrated Development Environment for the N8VEM CP/M single board computer, which allows many of the tedious parts of programming to be reduced to one keypress. Grateful acknowledgements to Peter Schorn for showing how batch files can be run on the SIMH and how to automatically close down the SIMH window once it has completed, and for maintaining this important piece of archival software. James Moxham Adelaide, Australia Moxhamj@internode.on.net