Wrote more utility programs to use with the Virtual 2315 Cartridge Facility

UPDATESECTOR IS GRAPHICAL EDITOR FOR ONE SECTOR OF A VIRTUAL 2315

This Python program opens a disk file used with the Virtual 2315 Cartridge Facility (V2315CF) allowing the user to edit the contents of one of the sectors on that virtual 2315 disk cartridge. A sector is 321 words long, a word on the IBM 1130 is 16 bits wide, and the words are displayed and edited in hexadecimal. A 2315 disk cartridge is organized into 203 cylinders and each cylinder is accessible by one of two read/write heads. Each of those 406 locations has four sectors of 321 words on it. 

At startup, the user selects the file in the V2315CF disk format, verifies that it is in the correct format, and then asks for the cylinder, head and sector number of the sector to be edited. 

The cartridge number and description are listed then the user is given a series of three pop up boxes to select the cylinder number, head number and sector number of the one sector they want to edit. A graphical grid editor is opened with a grid 

The grid is 16 columns wide and 21 rows long, the last row having only a single cell. The rows are the first two hex digits of the address of the word while the column headings are the third digit. Each cell is the word in the sector at that word number. For example, the bottom right cell shown above is at address 0x0EF and the value in that word is 0xDA34. The grid can be scrolled down to get words in addresses 0x0F0 to 0x140 as shown below.

Clicking in a cell allows entry of four hex characters before clicking elsewhere or hitting a tab to move to the next cell. The keys are validated - must be 0-9 or a-f and must be four long. Below you see the grid after I entered different values in two cells. At address 0x000 I typed in 3002 and then at address 0x016 I typed in AAAA. These replaced the prior values of 0x0000 in both cells. 

Once I click on the X in the upper right to dismiss the editor grid, the application writes the modified sector back to the virtual 2315 disk cartridge file and exits.

COMPAREDISKS WILL HIGHLIGHT EVERY SECTOR WHERE TWO 2315 DIFFER

The user selects the two files, each of which is validated to be in the correct format by the application before continuing to the comparison. The program then checks every word in the disk and reports the cylinder, head and sector number of each sector that has differences between the two files. 

The results are reported on a grid that pops up, with 8 columns across and 203 rows. The rows are the cylinder number in hexadecimal. The columns are:

• H0 S0 - head 0 sector 0
• H0 S1 - head 0 sector 1
• H0 S2 - head 0 sector 2
• H0 S3 - head 0 sector 3
• H1 S0 - head 1 sector 0
• H1 S1 - head 1 sector 1
• H1 S2 - head 1 sector 2
• H1 S3 - head 1 sector 3

Any sector where the data in the two files are different is colored yellow and has the cylinder number, head number and sector number reported. The cylinder number is given in hexadecimal and then decimal within parentheses. 

Simply click on the x in the upper right corner to close the grid and end the application.

AWAY UNTIL EARLY NEXT WEEK

I am visiting my daughter in Providence Rhode Island for a few days, but will be back and in the shop early next week.