S2E13 Synapse SynChron – Supplement

This episode features SynChron, originally released in 1983 by Synapse Software.  It was developed by Harry Guiremand.

Podcast: Download

Box and Supplement Scans

Scan of the front of the box:

SynChron Front


Scan of the back of the box:

SynChron Back


SynChron in Action


Boot splash screen:



Once booted, insert your data disk:

SynChron Boot 2


If your disk is blank, or otherwise not formatted for SynChron use, it will be initialized.  You have the option to start the initialization or try another disk.  See, you should have used those disk labels:

SynChron Init 1


Initialization in progress:

SynChron Init 2


Defining the year for the disk.  The year you input, and the subsequent year are defined and available for use:

SynChron Init 3


Main Menu

SynChron Main Menu



Empty calendar at start (year view), with selector on February.  Days represented as SUN through SAT:

SynChron Cal Empty


SynChron is Y2K compliant, and year view matches current calendars:

SynChron iOS Calendar


Full calendar (year view), selector on February:

SynChron Cal Full


Calendar (year view) filtered via Search (keyword HOLIDAY), selector on December:

SynChron Cal Search


Calendar month view for February (search tag in place for INVERSE):

SynChron Cal Month


Calendar day view for February 14.  Note the small gray line in the upper right of the text area which denotes the relative position of the cursor within the maximum text size (similar to a modern scrollbar):

SynChron Cal Day


Calendar day view showing the various formatting available, including male and female symbols; bullets; margins; word wrap; and index pointer movement:

SynChron Cal Day Styles


Keyword Menu

There are 3 options on the menu, 2 of which provide useful functions:

SynChron Keyword Menu


List Keywords

Listing the keywords.  Note that only the first 6 positions are significant:

SynChron Keyword List


Sort Keywords

Sorting the keywords:

SynChron Keyword Sort


Listing the keywords again proves they were sorted:

SynChron Keyword List Sorted


Password Menu

The ugly password menu.  Two functions, one to add or change, and one to remove:

SynChron Password Menu


Add Password

First confirm the addition:

SynChron Password Add


Next, input the password.  It can be 6 characters long.  Make sure no one is looking over your shoulders as it is not masked:

SynChron Password 2


Post input, it is displayed for a few seconds as confirmation:

SynChron Password 3


Remove Password

Removing the password requires confirmation in the form of a simple yes or no.  Unlike modern security, there is no re-authentication required:

SynChron Password Remove


Print Menu

The print menu has two primary functions.  The first (Print Control) is Print.  Print Format is for setting printer parameters:

SynChron Print Menu


Print Control

This is used for printing.  Enter the criteria:

SynChron Print 1


Turn the printer on:

SynChron Print 3


Watch as the printing takes place.  The current day being process is displayed I’m the middle of the screen.  The entries for the day scroll in the 3rd grey section:

SynChron Print 4


Print Format

Here you set printer parameters:

SynChron Print 5


Replace Year

This removes the current year and adds the 2nd year following (since the next year is already included).  Make a copy of your data disk if you want to preserve the current year entries.  Confirmation is required:

SynChron Replace 1


First the current year is removed:

SynChron Replace 2


Then the next year is added.  Note your yearly entries are not copied over:

SynChron Replace 3


Change Disk

This allows you to change years (or disks).  You are first asked for confirmation:

SynChron Change 1


Then you can remove the current disk and insert the want for the year you want:

SynChron Change 2


If it is password protected, you will be prompted to enter the password.  As with assigning the password, it is not masked during input, so make sure no one is looking at your screen:

SynChron Change 3


If you don’t get the password correct, you will be denied access:

SynChron Change 4




The contents of the disk can be seen in this screenshot (nope sorry, copy protected disk):

SynChron Files


Data Protection


The data is protected using cryptography, a modified simple replacement algorithm.   Clearly it does not meet modern encryption standards, but incredible for a consumer product in 1983.  I deciphered portions of it.

Model Entry

The model record (entry) I used to decipher the contents.  1/1/2345:

SynChron Crypt Model


Deciphering with Omnivore

Looking at the non passworded version of disk image with only the above entry:

SynChron Crypt Omnivore


Looking at the passworded version of disk image with only the above entry:

SynChron Crypt Omnivore Password


Crypto Key Map

Spreadsheet I put together showing the replacement algorithm:



Disk Image Map

Data locations I discovered in the disk image:

x0000 : Sector 0 - Unknown
x0090 : Sector 1 - Keywords
(16 max?, encoded as 8 chars, 6 chars plain text, last 2?)

x0100 : Sector 2 - Unknown
first 16 bytes blank

x0110 : Number of entries?
00 = no data
03 = 1 record ?
07 = 30 records ?

x0180 : Sector 3 - 1st Data Entry Block
first 16 bytes blank

x0190 -> x01FF : Data
Data in each sector
... repeat, as 1st Data Entry Block

xB410 : Unknown
1F   (2 records)

xB43D : Unknown
FF 3F  (always the same)

xB46A : Signature
3E 5E 23 51 24 25   (always the same)
>  ^  #  Q  $  %

xB470 : Password
(all bytes change, last 6 are actual password)
69 B5 4F F4 2F D7 EB E8 E9 EE EF EC    123456
A9 80 3E 57 7B B9 93 94 8C 9F 88 89    INVERS
59 66 8E 93 49 E5 9B 9B 9B 9B 9B 9B    AAAAAA  (9B=155)
33 CF 45 9C 3C 7C 98 98 98 98 98 98    BBBBBB  (98=152)
54 C6 CF F3 37 02 99 99 99 99 99 99    CCCCCC  (99=153)

xB48A : Date
LSBMSBLSBMSB - Primary Year, Next Year
29 09 2A 09    2345 2346
2A 09 2B 09    2346 2347
E0 07 E1 07    2016 2017

xB490 : Calendar Day Map
Sector ID’s for days entry - 2 bytes each (LSB/MSB)

xB490/1 = 01/01 (First day mapping)

xB78C/D = 12/31 (Last day mapping - non leap)

xBAE0 : Number of entries?
50 00 00 00 01         0 and 1 records
50 00 00 00 02         2 records (0101,0102)
50 00 00 00 1F 00 0B   2 records (0101,1231)
50 00 00 00 0B 00 04   30 records



Printing the entire calendar.  You could easily accomplish the same thing with a word processor or text editor:


Printing just holidays using the HOLIDAY keyword to filter the output:



The manual is available on AtariMania and the Internet Archive.


Show Links:


Bit Rating 6

Intro music is an excerpt from a chip tune by Wizwars named 8 Bit Raceway.  It is used under Creative Common license Attribution-NonCommercial-ShareAlike 3.0 United States.

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