Two Battles, Similar Results, Different Assessment

In this post, I’m going to briefly compare two Civil War battles. Both battles had very similar results. Both of these battles were surprise attacks on strongly entrenched defenders.

The Battle of the Crater

Union Attacker: 8,500 troops and suffered losses of 3798 men

Confederate Defender: 6,100 troops and lost 1491 men

Result: Attackers were thrown back around midday

The Battle of Fort Stedman

Confederate Attacker: 10,000 troops and lost 4000 men

Union Defender: 14898 troops and lost 1044 men

Result: Attackers were defeated by around 8:00AM

Detailed accounts of both battles reveal a pretty similar chain of events. At first a breakthrough, but confusion and strong counterattacks caused high casualties among the attackers. In both cases, it was particularly difficult for the attackers to find a way to return to friendly lines.

Both attacks involved surprise in order to initiate the breakthrough. The Union Army used a mine to blow a hole in the Confederate lines to start the Battle of the Crater, while the Confederates used men posing as deserters to surprise and overcome the initial defense of Fort Stedman. The Union had more men to engage in the defense of Fort Stedman, and were able to defeat the assault early in the morning. The Confederates had less men involved in the Battle of the Crater, and took longer to completely throw back the assault.

To me, one of the the most interesting things about these two battles is how the results were reported by the defeated army commanders.

The complete text of all of these messages can be found online in the Official Records, just follow the embedded links and you will find yourself on the right page. Scroll down to find the relevant messages.

The day after the Battle of the Crater, General Grant sent a telegram to his Chief of Staff, General Halleck, and classified the battle as a disaster. The next day, in another letter to Halleck, a court of inquiry was requested by General Grant. Generals Burnside and Ledlie lost their commands and a number of other Union Generals were censured by the inquiry. In contrast, Lee’s message to Secretary of War, Breckinridge, was in a more matter of fact style. He did under-report the losses as “not heavy”. Lee was very complimentary of his troops and their leaders.

I think that there are some questions that are worth asking about the reports of each commander.

  • Why was Grant so tough on his leaders? Did he believe that he needed a scapegoat, or did he feel that some of those leaders needed to be replaced?
  • Why was Lee so indifferent to a bad day? Remember that at the time of this battle, the Confederacy was on it’s last legs. Did he expect the attack to fail before it was launched or was he maintaining a somewhat positive outlook to keep moral up?

One last point. It is interesting to think about how each of the losing commanders initial reports has carried down through history to today. Even though the results of each battle was about the same, the modern historians perception of the management of the two battles largely mirrors the commanders initial reports.

More on the Dictator Mortar

Last year, during my research in the National Archives, I took many pictures of entries from a journal kept by the US Military Rail Road Construction Corps. One of these entries discusses the construction of a platform for the 13″ mortar. The weapon now known as the “Dictator.”

USMRR Construction Corps - diary entry 13" mortar platform
USMRR Construction Corps – diary entry 13″ mortar platform

Thursday, August 25th, 1864

Mills gang “Carpenters” Erecting platform up the railroad for large 13 inch Mortar intended to shell Petersburg. Browns gang laying side track to the same, which is in rear of Battery No. 5, in front of Petersburg 1 1/2 miles distance.

Though this entry notes that the intention was to shell Petersburg, the reality was different. The 13″ mortar was positioned with an intention to suppress Confederate artillery that were posted in a rather advantageous position that flanked the right of the Union lines. The artillery in this position troubled the Union troops from the Second Battle of Petersburg through to the end of the siege, as the Union troops never were able to effectively suppress it. The nature of this flanking position can be clearly seen in this map of the positions of the Union 1st Division of the 9th Corps on April 1st, 1865. I added the red arrows showing the field of fire of the flanking Confederate batteries.

Map-1st Div., Ninth Corp,April,1 1865
Map-1st Div., Ninth Corp,April,1 1865

More can be found out about this problem and the 13″ mortar’s role in it, in the book, “History of the First Connecticut Artillery.” This unit operated the Union siege artillery during the siege of Petersburg, including the 13″ mortar. This regimental history is put together much like the Official Records, and is largely a compilation of surviving documents concerning the regiment. There are some additional notes added by the editors. This particular note spans pages 68 and 69 and describes how the 13″ mortar was used.

13 Mortar from 1st Conn History
13″ Mortar from History of 1st Conn Artillery

Though I haven’t done an exhaustive search through this book, the earliest reference to the 13″ mortar is on July 8th, 1864. In this memo, it is clear that the 13″ mortar is already in position on a truck carriage.

Capt. Osborne Takes Charge of the Dictator
Capt. Osborne Takes Charge of the Dictator

This additional message seems to indicate that the 13 inch mortar is just being brought up into line on the 8th, so Captain Osborne must have been the first commander of this mortar.

13 inch mortar into position
13 inch mortar into position

Right now, that’s all I have time for. I’ll elaborate on why there are orders to build a platform for the 13 inch mortar on the 25th of August, more than two weeks after it was first put into service, in a follow up post.

hmm- what will we see next

Today Gizmoto reported on this iPhone enclosed in a case that is supposed to made from a piece of authentic Apple 1 circuit board

The biggest problem with this product is the likelihood that the circuit board fragment is from a reproduction. On that same site are images of what are unquestionably reproduction Apple 1 circuit boards. I’m quite sure about these images since no Apple 1 circuit boards have ever been found that weren’t populated with components.

Apple II Keyboard Enclosure

Quite a while ago, Wendell Sander sent me an example of his Apple 1/Apple ][ compatible keyboard design. Over the past couple of years, I’ve used it with my SCELBI as it can also be connected to a SCELBI keyboard interface. I didn’t have an enclosure, but had it mounted on a couple of blocks of wood.

For a long time, I’ve envisioned building a proper enclosure for it. Well, I finally got around to doing just that. I recycled some red oak that I had cut to a bit less than 3/8″ thick and had used for a while in another project that is now not needed.

Keyboard Enclosure
Keyboard Enclosure

I think it looks quite nice. There is no rear cover, but I suppose I could add a sheet metal cover , if I decided I really needed one.

keyboard enclosure, back
keyboard enclosure, back

For those that are interested in making their own Apple II compatible keyboard enclosure, the following drawing can be used to cut out the faceplate.

Keyboard Layout

Making Progress on SCELBI Hardware Manual

Back in 2017, I started on a hardware manual for the SCELBI computers. This originally was a digital copy of the original SCELBI 8B hardware assembly manual, which described construction and basic operation of the SCELBI 8B CPU. The original SCELBI 8B manual was 86 pages long and did not include any software or information on peripherals. Over the past couple of years, I have greatly expanded this manual. The draft now includes the following sections:

  • History
  • Printed wiring board assembly
  • Chassis assembly
  • Power supply
  • Installation and check out procedures
  • Peripherals
  • Schematics, parts lists and technical notes
  • Enhancements and modifications
  • System software and utilities

My goal, up to now, was to gather as much relevant content as possible and get it into a draft manuscript. At his point, I think I have added most of the content that I think is important into the draft and will now start work on doing a complete job of editing. The goal would be to put the manuscript into a reasonable condition where it could possibly be published. This will take a while, as the document is currently 274 pages long, and up to now, there has been almost no serious editing done.

Book Review – A Campaign of Giants – The Battle For Petersburg: Volume 1: From the Crossing of the James to the Crater – A. Wilson Greene

I’ve long held an interest in the siege of Petersburg, which was the decisive campaign that lead to the end of the American Civil War. Despite the importance of this siege, books that cover it in detail are few in number, especially when compared with detailed coverage of most of the great battles of 1862 and 1863. When I heard of this new book in 2018, which promised the coverage that I was looking for, I knew I had to read it and I bought a copy soon after it was released.

A Campaign of Giants
A Campaign of Giants

Though the book has good reviews, currently rating 4.6 on Amazon, it took me two years to finish it. Though very well written, I found parts of the book hard to read. I think that is because my point of view differs greatly from that of the author. The author is extremely critical of the generalship of the Northern leaders. While Greene mentions some of the mistakes of the Southern commanders, it’s almost as if Greene was still propagating some aspects of the myth of the “Lost Cause.” In my mind, Greene doesn’t really appear to understand the difficulty of what Grant and his armies were attempting to achieve.

Though this is a battle book, I found coverage of the various engagements, inconsistent. With the vast majority of these kinds of books, the author, after describing a battle, will summarize the results in terms of ground lost or gained and resulting casualties. This book is no different and some of the smaller engagements are described in this fashion, with little to no detail as to what happened. To me, this approach strikes me as completely ignoring the horrors of war, almost antiseptic in nature. The following example shows how a clash that cost 140 Confederate casualties and an unreported number of Federal casualties, is covered in only two sentences. I understand how a book covering so many events can only devote so much text to such a small engagement, but it still bothered me a bit.

However, at the other end of the spectrum, the description of the Battle of the Crater is extremely graphic and detailed. Every American should read Greene’s account of that battle. This account should dispel any misconceptions modern Americans have about the Civil War being a “clean” war. In actuality, it was an ugly, dirty, horrid affair. This account also explores the horrors of racism that persists in our society to this very day.

Just to end this review on a positive note, I found the description of Wilson’s raid very engaging and interesting, maybe because I knew very little about the raid before reading this book.

Finally, since I’m done with this book, and I don’t have room on my shelves for more books, I’ll send my copy to the first of my blog readers that reaches out to me expressing an interest in reading it.

Easy TTY Emulation on an Apple ][e

Back in 2015, I partially described how I used an early Apple serial card in an Apple ][ to provide a “glass” TTY emulation in order to check out some of my SCELBI software and interfaces. Since I don’t have a real TTY, I always had to set up the Apple ][ and download an emulation program via cassette tape interface in order to test the SCELBI with an TTY interface. Over the years, this has been an annoying bit of hassle, mainly because I usually forgot exactly what version of the software that I needed to download, exactly where in memory to download it, and what slot to put the serial card into.

I knew that I could create a turnkey power on and go solution by designing and building a custom Apple ][ peripheral board. I just needed to copy the current loop interface from the Apple Serial card to a Superproto board and drive it with the Superproto’s 6522 VIA interface hardware. I knew I could easily port the program I had already written to run right out of the Superproto’s EERPOM. I first thought about doing this years ago.

Finally I started to do something at the beginning of this year, when I ordered the few required hardware components that I didn’t have in my stash. These parts came in right away, but, until now, I haven’t found the time to build up the board and port the software.

TTY Card
TTY Card

Well, I finally found the time to get this project working. I think the result is pretty cool. To connect a TTY with a 110 baud current loop interface to my SCELBI, I just connect the Apple ][e to a monitor, the SCELBI and power it up. No need to bother with floppy disks or cassette interfaces, or anything else. Since this card looks like a Disk ][ to the Apple, the Apple will automatically boot the TTY application, which resides in the Superproto’s EEprom.

I could potentially add logging, paper tape emulation and scroll back capability to this application, but I probably will not proceed with those ideas, at least anytime soon.

One other thing I might do, is create a version of software that will work at 45.45 baud and the Baudot charactor code, so I can use it with RTTY applications. I have done a simple version of this software for the Apple serial card, so it shouldn’t be too hard to port over. Since the Superproto supports multiple banks of memory in the EEPROM, I can use the same board and just put the RTTY app in a separate bank, and use the bank select jumpers to switch between TTY and RTTY applications.

Someday, I might make a custom card for this design, but I’m not going to do this unless I hear about some kind of demand for such a card.

Let me know if you are interested in seeing more details of the software and hardware design.

SCELBI Fast Loader Peripheral

Booting the SCELBI without an integrated EPROM boot loader/monitor can be an extremely difficult and time consuming process.  The first issue of the SCELBI newsletter described a very simple peripheral that makes this process easier.  I’ve known about this simple device for years, but until now, never built one. Well it turns out that I should have built one when I built my SCELBI-8H. It makes for a huge improvement in data entry capabilities of a SCELBI that doesn’t have a EPROM monitor, like my 8H, as it was initially constructed.

SCELBI Fast Loader
SCELBI Fast Loader

The fast loader peripheral is a simple device that relies upon a tiny four byte long program which can easily be toggled into memory with the SCELBI’s front panel.

The device is connected to any input port with a standard SCELBI peripheral cable. There is already a pull-up on each input, so all that needs to be done, is to either leave the input floating, in which case the SCELBI’s internal pull up resister will pull the input level high or connect the input to ground, which will force the input low. The operator sets each input to a high or low state with a simple DPST switch.

Fast Loader Schematic
Fast Loader Schematic

The way this peripheral is operated is as follows.  Using the front panel, the operator toggles the four byte long, fast loader program into memory, starting at location 0, and then sets the H and L registers to point to where the data needs to be written.

When run, the fast loader program will read the input port connected to the fast loader, writes the data to memory, increments the L register and then halts.  Once the program is started, the operator enters a RST 0 instruction into the SCELBI front panel toggle switches.  While still halted, the operator enters the data to be written into the next memory location into the fast loader toggle switches.  The operator presses the interrupt button on the SCELBI front panel and then the run button.  The program will jump to zero because of the RST 0 instruction that is set on the front panel. The program at location zero will read the input port, deposit the data to memory pointed to by the H and L registers, increment the L register and then halt again. The process is repeated until the operator has entered all the desired data into the SCELBI’s memory.

The fast loader program follows. This version assumes the fast loader peripheral is connected to input port zero, but other ports can be used by changing the INP instruction.

Line Addr.  CodeBytes   Source LineLine Addr.  CodeBytes   Source Line
—- —— ———– ———————————-
01                    START:ORG 000#000
02 00-000 101 INP 000 ; read port 0
03 00-001 370     LMA ; save to memory
04 00-002 060         INL ; increment L
05 00-003 000         HLT ; stop

 This program doesn’t handle the case of register L wrapping, but a few more instructions could be added to increment register H, if L wraps. Most boot programs should be designed fit into a single page, so this should not be necessary.

Here is a picture of the inside of the fast loader that I built. You couldn’t possibly come up with a simpler design for a peripheral device.

Fast Loader Interior
Fast Loader Interior

Debugging the SCELBI Power Supply

I had a bit of trouble debugging the 5 volt side of this power supply. First symptoms I noticed was an inability to regulate under load. As the load increased the output voltage dropped significantly to the point where the computer would not work. In my mind, this probably meant that the regulator portion wasn’t working.

These sort of Power-One linear supplies use a uA723 regulator to do the job. You feed reference voltage and output voltage (usually divided by a resistor network) into the regulator and the output of this chip controls one or more power transistors to supply the desired voltage. You can find more about these supplies on this nice Power-One hacker page.

Though the Power-One linear supplies are all similar in design, they differ in details. I made a schematic of this particular power supply so that I could properly debug it.

Power-One Schematic
Power-One Schematic

After much probing, I could find no issues with the regulator circuit or the regulator chip. This really confused me, as the power supply regulation wasn’t operating correctly. After some hard thinking, I wondered if the problem might actually be with my measurement. Since my oscilloscope was broken, I switched my DMM to AC mode and as soon as a load was applied, I detected a several volts of ripple. Using a DMM to check ripple by putting it into AC mode is a trick that I learned somewhere along the line and has come in handy a number of times.

Realizing that most likely the smoothing capacitor, wasn’t smoothing, I jumpered in a fairly large capacity smoothing capacitor that I had in my stash. Sure enough, the ripple disappeared and the power supply output remained stable under different loads, just like it was supposed to.

I ordered an appropriate replacement and a spare. I replaced the smoothing capacitor and the power supply worked flawlessly for the remainder of this original SCELBI-8B’s checkout.

This isn’t the quite the end of the story. After I returned the system to the owner, the power supply failed again. Since symptoms were the same as before, I thought that perhaps the replacement capacitor failed during shipping, I sent a second capacitor to the owner, who wired it in parallel to the replacement cap, which solved the issue (again). Whenever I order parts, I almost always order spares, as shipping is often more expensive than the parts themselves. Having a spare on hand certainly was helpful this time around.

I’m not sure what happened during shipping of this system. Generally, I’m pretty reluctant to repair old computers, because of the high risk of new issues appearing during return shipping. I only took on this job because of the rarity of a SCELBI-8B and the chance I would have to further document an example.

Details of a Factory SCELBI Power Supply

SCELBI Power Supply

Here is the front of the factory power supply that is part of the SCELBI-8B system described in the last post. A simple on-off switch, three banana plugs/binding posts, (+5 volts/-9 volts/ground) and an Amphehol 4 pin socket for connecting power to the chassis make up the controls and connections on the front. On the back is a fuse and fitting for passing the AC power cord through the back of the chassis.

The inside reveals space at the top of the picture for a 110 volt AC fan which is bolted to the cover. The cover has ventilation holes drilled in both ends to allow the fan to draw in cooling air. Two Power-One supplies make up the power supplies. One is 5 volts and the other is a Power-One 12-15 volt supply modified to output 9 volts. The positive output of the 9 volt supply is connected to the negative output of the 5 volt supply which becomes ground for the system. The negative output of the 9 volt supply becomes -9 and the positive output of the 5 volt supply supplies +5 volts to the system.

All in all, the whole thing is an extremely simple affair, the only complication being the changing of a resistor in order to covert the 12-15 volt supply to a 9 volt supply. This unit did not actually use banana plugs for power delivery to peripherals, but ordinary hook-up wire connected to the binding posts.

In my next post I will describe the problem with the power supply and how I resolved it.